PROSPECTUS AND STATEMENT OF ADDITIONAL …...prospectus and statement of additional information (“sai”) supplement northern institutional funds money market portfolios — williams

M O N E Y M A R K E T P O R T F O L I O S

P R O S P E C T U S S U P P L E M E N T

NORTHERN INSTITUTIONAL FUNDSMONEY MARKET PORTFOLIOS — WILLIAMSCAPITAL SHARES

SUPPLEMENT DATED OCTOBER 30, 2020 TO THEPROSPECTUS DATED APRIL 1, 2020, ASSUPPLEMENTED

1. The following statement on the cover of the Prospectus ishereby deleted: “Offered to clients of Siebert WilliamsShank & Co., LLC”.

2. The entire sub-section entitled “PORTFOLIOSUMMARIES – U.S. GOVERNMENT SELECTPORTFOLIO – PURCHASE AND SALE OF PORTFOLIOSHARES” on page 12 of the Prospectus is deleted andreplaced with the following:

You may purchase Williams Capital Shares of the Portfoliothrough an authorized intermediary generally with nominimum initial investment.

On any business day, you may sell (redeem) or exchangeWilliams Capital Shares of the Portfolio through yourinstitutional account by contacting your Northern Trustaccount representative or authorized intermediary. If youpurchase Williams Capital Shares of the Portfolio directlyfrom the Trust, you may sell (redeem) or exchange yourshares in one of the following ways:

• By Mail – Send a written request to: NorthernInstitutional Funds, P.O. Box 75986, Chicago,Illinois 60675-5986.

• By Telephone – Call the Northern Institutional FundsCenter at 800-637-1380.

• By Wire – Authorize wire redemptions on your NewAccount Application and have proceeds sent byfederal wire transfer to a previously designated bankaccount (the minimum redemption amount by thismethod is $10,000).

3. The entire sub-section entitled “PURCHASING ANDSELLING WILLIAMS CAPITAL SHARES – INVESTORS”on page 16 of the Prospectus is deleted.

4. The reference to “SWS” in the last paragraph under thesub-section entitled “PURCHASING AND SELLINGWILLIAMS CAPITAL SHARES – SHARE CLASSES” onpage 16 of the Prospectus is deleted and replaced with thefollowing:

Siebert Williams Shank & Co., LLC (“SWS”)

5. The entire sub-section entitled “ACCOUNT POLICIESAND OTHER INFORMATION – EXCHANGEPRIVILEGES” on page 21 of the Prospectus is deleted.

6. The entire sub-section entitled “ACCOUNT POLICIESAND OTHER INFORMATION – ADVANCENOTIFICATION OF LARGE TRANSACTIONS” onpage 22 of the Prospectus is deleted and replaced with thefollowing:

ADVANCE NOTIFICATION OF LARGE TRANS-ACTIONS. The Trust requests that shareholders giveadvance notice to the Transfer Agent by 11:00 a.m. Centraltime if they intend to place a purchase or redemptionorder of $5 million or more on a Business Day. For otherlarge purchase or redemption orders below $5 million, theTrust requests that a shareholder give advance notice tothe Transfer Agent as early as possible in the day.

7. All references to the “SWS dedicated phone line at866-926-3863” in the Prospectus are deleted.

Please retain this Supplement with your Prospectus for future reference.

50 South LaSalle Street

P.O. Box 75986

Chicago, Illinois 60675-5986

800-637-1380

www.northerninstitutionalfunds.com

MANAGED BY NIF SPT WC (10/20)

NORTHERN INSTITUTIONAL FUNDS PROSPECTUS

M O N E Y M A R K E T P O R T F O L I O S

P R O S P E C T U S A N D S T A T E M E N T O F A D D I T I O N A L I N F O R M A T I O N ( “ S A I ” )S U P P L E M E N T

NORTHERN INSTITUTIONAL FUNDSMONEY MARKET PORTFOLIOS — WILLIAMSCAPITAL SHARES

SUPPLEMENT DATED MAY 18, 2020 TOPROSPECTUS AND SAI DATED APRIL 1, 2020

PENDING LIQUIDATION OF PRIMEOBLIGATIONS PORTFOLIO

The Board of Trustees (the “Board”) of Northern InstitutionalFunds (the “Trust”) has determined, after consideration of anumber of factors, that it is in the best interests of the PrimeObligations Portfolio (the “Portfolio”) and its shareholders thatthe Portfolio be liquidated and terminated on or about July 10,2020 (the “Liquidation Date”) pursuant to a plan of liquidationapproved by the Board. The Liquidation Date may be changedat the discretion of the Trust’s officers. The pending liquidationof the Portfolio may be terminated and/or abandoned at anytime before the Liquidation Date by action of the Board of theTrust.

As of the date of this supplement, Williams Capital Shares ofthe Portfolio have not commenced operations and are notoffered for purchase.

Please retain this Supplement with your Prospectus and SAI for future reference.

50 South LaSalle Street

P.O. Box 75986

Chicago, Illinois 60675-5986

800-637-1380

www.northerninstitutionalfunds.com

MANAGED BY NIF SPT WC (5/20)

NORTHERN INSTITUTIONAL FUNDS PROSPECTUS

P R O S P E C T U S D AT E D A P R I L 1, 2 0 2 0

P R I M E O B L I G AT I O N S P O R T F O L I OW I L L I A M S C A P I TA L S H A R E S

( W C P X X )

U . S . G O V E R N M E N T S E L E C T P O R T F O L I OW I L L I A M S C A P I TA L S H A R E S

( W C G X X )

Offered to clients of Siebert Williams Shank & Co., LLC

You could lose money by investing in the Portfolios.Because the share price of the Prime Obligations Portfolio will fluctuate, when you sell your shares they may be worth more or less than what you originally paid for them. The Prime Obligations Portfolio may impose a fee upon sale of your shares or may temporarily suspend your ability to sell shares if the Portfolio’s liquidity falls below required minimums because of market conditions or other factors.Although the U.S. Government Select Portfolio seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so.An investment in a Portfolio is not a deposit of any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation (“FDIC”), any other government agency, or The Northern Trust Company, its affiliates, subsidiaries or any other bank. The Portfolios’ sponsor has no legal obligation to provide financial support to the Portfolios, and you should not expect that the sponsor will provide financial support to the Portfolios at any time.The Securities and Exchange Commission (“SEC”) has not approved or disapproved these securities or passed upon the adequacy of this Prospectus. Any representation to the contrary is a criminal offense. Beginning on January 1, 2021, as permitted by regulations adopted by the SEC, paper copies of Northern Institutional Funds shareholder reports will no longer be sent by mail, unless you specifically request paper copies of the reports from Northern Institutional Funds or from your financial intermediary, such as a broker-dealer or bank. Instead, the reports will be made available on the Portfolios’ website (northerntrust.com/institutional) and you will be notified by mail each time a report is posted and provided with a website link to access the report.If you have already elected to receive your shareholder reports electronically, you will not be affected by this change and you need not take any action. You may elect to receive shareholder reports and other communications from Northern Institutional Funds electronically at any time by contacting your financial intermediary (such as a broker-dealer or bank) or, if your account is held directly with Northern Institutional Funds, by calling the Northern Institutional Funds Center at 800-637-1380 or by sending an e-mail request to: [email protected] may elect to receive all future reports in paper free of charge. If you invest through a financial intermediary, please contact your financial intermediary to continue receiving paper copies of your shareholder reports. If you invest directly with Northern Institutional Funds, you can inform Northern Institutional Funds that you wish to continue receiving paper copies of your shareholder reports by calling the Northern Institutional Funds Center at 800-637-1380 or by sending an e-mail request to: [email protected]. Your election to receive reports in paper will apply to all Northern Institutional Funds you hold in your account at the financial intermediary or through an account with Northern Institutional Funds. You must provide separate instructions to each of your financial intermediaries.

N O R T H E R N I N S T I T U T I O N A L F U N D SM O N E Y M A R K E T P O R T F O L I O S

M O N E Y M A R K E T P O R T F O L I O S — W I L L I A M S C A P I T A L S H A R E S

T A B L E O F C O N T E N T S

3 PORTFOLIO SUMMARIES

3 PRIME OBLIGATIONS PORTFOLIO

9 U.S. GOVERNMENT SELECT PORTFOLIO

13 INVESTMENT ADVISER

14 MANAGEMENT FEES

15 OTHER PORTFOLIO SERVICES

16 PURCHASING AND SELLING WILLIAMS CAPITAL SHARES

16 INVESTORS

16 SHARE CLASSES

16 PURCHASING WILLIAMS CAPITAL SHARES

16 OPENING AN ACCOUNT

17 SELLING WILLIAMS CAPITAL SHARES

18 LIQUIDITY FEES AND REDEMPTION GATES—PRIME

OBLIGATIONS PORTFOLIO

19 ACCOUNT POLICIES AND OTHER INFORMATION

24 DISTRIBUTIONS AND TAX CONSIDERATIONS

26 SECURITIES, TECHNIQUES AND RISKS

26 ADDITIONAL INFORMATION ON INVESTMENT OBJECTIVES,

PRINCIPAL INVESTMENT STRATEGIES AND RELATED RISKS,

DESCRIPTION OF SECURITIES AND COMMON INVESTMENT

TECHNIQUES

40 FINANCIAL HIGHLIGHTS

44 FOR MORE INFORMATION

MONEY MARKET PORTFOLIOS 2 NORTHERN INSTITUTIONAL FUNDS PROSPECTUS


P O R T F O L I O S U M M A R I E S

P R I M E O B L I G A T I O N S P O R T F O L I O

I N V E S T M E N T O B J E C T I V E

The Portfolio seeks to maximize current income to the extentconsistent with the preservation of capital and maintenance ofliquidity by investing exclusively in high quality money marketinstruments.

F E E S A N D E X P E N S E S O F T H E P O R T F O L I O

This table describes the fees and expenses that you may pay ifyou buy and hold Williams Capital Shares of the Portfolio.

Shareholder Fees (fees paid directly from your investment)

None

Annual Portfolio Operating Expenses (expenses that you pay each year asa percentage of the value of your investment)

WilliamsCapitalShares

Management Fees 0.13%

Other Expenses(1) 0.03%

Transfer Agent Fees 0.02%

Service Fees None

Other Operating Expenses 0.01%

Total Annual Portfolio Operating Expenses 0.16%

Expense Reimbursement(2) (0.01)%

Total Annual Portfolio Operating Expenses After ExpenseReimbursement 0.15%

(1) “Other Expenses” have been estimated for the current fiscal year.

(2) Northern Trust Investments, Inc. has contractually agreed to reimburse a por-tion of the operating expenses of the Portfolio (other than certain exceptedexpenses, i.e., Acquired Fund Fees and Expenses, service fees, the compensa-tion paid to each Independent Trustee of the Trust, expenses of third partyconsultants engaged by the Board of Trustees, membership dues paid to theInvestment Company Institute and Mutual Fund Directors Forum, expenses inconnection with the negotiation and renewal of the revolving credit facility,extraordinary expenses and interest) to the extent the “Total Annual PortfolioOperating Expenses” exceed 0.15%. This contractual limitation may not beterminated before April 1, 2021 without the approval of the Board of Trustees.

E X A M P L E

The following Example is intended to help you compare thecost of investing in Williams Capital Shares of the Portfoliowith the cost of investing in other mutual funds. The Exampleassumes that you invest $10,000 in the Portfolio for the timeperiods indicated and then redeem all of your shares at the endof those periods. The Example also assumes that yourinvestment has a 5% return each year and that the Portfolio’s

operating expenses remain the same. Although your actualcosts may be higher or lower, based on these assumptions yourcosts would be:

1 Year 3 Years 5 Years 10 Years

Williams Capital Shares $15 $51 $89 $204

P R I N C I P A L I N V E S T M E N T S T R A T E G I E S

The Portfolio seeks to achieve its objective by investing in abroad range of high-quality, U.S. dollar-denominatedgovernment, bank and commercial obligations that areavailable in the money markets, including:

▪ Obligations of U.S. banks (including obligations of foreignbranches of such banks);

▪ Obligations of foreign commercial banks;

▪ Commercial paper and other obligations issued or guaranteedby U.S. and foreign corporations and other issuers;

▪ Corporate bonds, notes, paper and other instruments that areof high quality;

▪ Asset-backed securities and asset-backed commercial paper;

▪ Securities issued or guaranteed as to principal and interest bythe U.S. government or by its agencies, instrumentalities orsponsored enterprises and custodial receipts with respectthereto;

▪ Securities issued or guaranteed by one or more foreigngovernments or political subdivisions, agencies orinstrumentalities;

▪ Repurchase agreements; and

▪ Municipal securities issued or guaranteed by state or localgovernmental bodies.

Under normal market conditions, the Portfolio will invest atleast 25% of its total assets in securities issued by companies inthe financial services group of industries. Companies in thefinancial services group of industries include but are not limitedto U.S. and non-U.S. companies involved in banking, mortgage,consumer or specialized finance, investment banking, securitiesbrokerage, asset management and custody, insurance, financialinvestment, real estate and mortgage finance and financialconglomerates, and related asset-backed securities. The Portfoliomay, however, for temporary defensive purposes, invest lessthan 25% of its total assets in the financial services industry ifwarranted due to adverse economic conditions or if investingless than 25% of its total assets in the financial services industryappears to be in the best interest of shareholders.

NORTHERN INSTITUTIONAL FUNDS PROSPECTUS 3 MONEY MARKET PORTFOLIOS



The Portfolio operates as an “institutional money market fund”under Rule 2a-7 of the Investment Company Act of 1940, asamended. As an “institutional money market fund” underRule 2a-7, the Portfolio is (1) required to sell and redeem itsshares at its net asset value (“NAV”) rounded to the fourthdecimal place (e.g., $1.0000) reflecting market-based values ofthe Portfolio’s holdings, and (2) the Board of Trustees (the“Board”) will be permitted to impose a “liquidity fee” onredemptions from the Portfolio (up to 2%) or temporarilyrestrict redemptions from the Portfolio for up to 10 businessdays during a 90-day period, as described in more detail under“Purchase and Sale of Portfolio Shares.”

The Securities and Exchange Commission (“SEC”) imposesstrict requirements on the investment quality, maturity,diversification and liquidity of the Portfolio’s investments.Accordingly, the Portfolio’s investments must have a remainingmaturity of no more than 397 days and must be high quality.The Portfolio’s investment adviser may consider, among otherthings, credit, interest rate and prepayment risks as well asgeneral market conditions when deciding whether to buy or sellinvestments for the Portfolio.

P R I N C I P A L R I S K S

As with any investment, you could lose all or part of yourinvestment in the Portfolio, and the Portfolio’s performancecould trail that of other investments. The Portfolio is subject tocertain risks, including the principal risks noted below, any ofwhich may adversely affect the Portfolio’s NAV, trading price,yield, total return and ability to meet its investment objective.Each risk noted below is considered a principal risk of investingin the Portfolio, regardless of the order in which it appears. Thesignificance of each risk factor below may change over time andyou should review each risk factor carefully.

CREDIT (OR DEFAULT) RISK is the risk that the inability orunwillingness of an issuer or guarantor of a fixed-incomesecurity, or a counterparty to a repurchase or other transaction,to meet its principal or interest payments or other financialobligations will adversely affect the value of the Portfolio’sinvestments and its returns. Changes in the credit rating of adebt security or of the issuer of a debt security held by thePortfolio could have a similar effect. The Portfolio could also bedelayed or hindered in its enforcement of rights against anissuer, guarantor or counterparty.

INTEREST RATE RISK is the risk that during periods of risinginterest rates, the Portfolio’s yield (and the market value of itssecurities) will tend to be lower than prevailing market rates; inperiods of falling interest rates, the Portfolio’s yield (and themarket value of its securities) will tend to be higher. Securitieswith longer maturities tend to be more sensitive to changes in

interest rates, causing them to be more volatile than securitieswith shorter maturities. Securities with shorter maturities tendto provide lower returns and be less volatile than securities withlonger maturities. If interest rates rise, the Portfolio’s yield maynot increase proportionately, and the maturities of incomesecurities that have the ability to be prepaid or called by theissuer may be extended. Changing interest rates may haveunpredictable effects on the markets and the Portfolio’sinvestments. Recent and any future declines in interest ratelevels could cause the Portfolio’s earnings to fall below thePortfolio’s expense ratio, resulting in a negative yield and adecline in the Portfolio’s share price. A general rise in interestrates may cause investors to move out of fixed incomesecurities on a large scale, which could adversely affect the priceand liquidity of fixed income securities and could also result inincreased redemptions for the Portfolio. Fluctuations in interestrates may also affect the liquidity of fixed income securities andinstruments held by the Portfolio.

PREPAYMENT (OR CALL) RISK is the risk that because manyissuers of fixed-income securities have an option to prepay theirfixed-income securities, the exercise of such option may resultin a decreased rate of return and a decline in value of thosesecurities and accordingly, a decline in the Portfolio’s NAV.Issuers may be more likely to prepay their securities if interestrates fall. If this happens, the Portfolio will not benefit from therise in the market price of the securities that normallyaccompanies a decline in interest rates, and will be forced toreinvest prepayment proceeds at a time when yield on securitiesavailable in the market are lower than the yield on prepaidsecurities. The Portfolio may also lose any premium it paid topurchase the securities.

GUARANTOR (OR CREDIT ENHANCEMENT) RISK is the risk thatchanges in credit quality of a U.S. or foreign bank, insurancecompany or other financial institution or such entity’s failureto fulfill its obligations could cause the Portfolio’s investmentsto decline in value. Adverse developments in the banking orbond insurance industries also may negatively affect thePortfolio.

LARGE SHAREHOLDER RISK is the risk that the Portfolio mayexperience adverse effects when certain large shareholders,including funds or accounts over which the Portfolio’sinvestment adviser or an affiliate of the investment adviser hasinvestment discretion, purchase or redeem large amounts ofshares of the Portfolio. Such large shareholder redemptions,which may occur rapidly and unexpectedly, may cause thePortfolio to sell its securities at times it would not otherwise doso, which may negatively impact its liquidity and/or NAV. Suchsales may also accelerate the increase of taxable income toshareholders if these sales result in gains, and may also increasetransaction costs. In addition, large redemptions could lead to




an increase in the Portfolio’s expense ratio due to expensesbeing allocated over a smaller asset base. Large share purchasesof the Portfolio may adversely affect the Portfolio’sperformance to the extent that the Portfolio is delayed ininvesting or otherwise maintains a larger cash position than itordinarily would.

COMMERCIAL PAPER RISK. Investments in commercial paperare subject to the risk that the issuer cannot issue enough newcommercial paper to satisfy its obligations with respect to itsoutstanding commercial paper, also known as rollover risk.Commercial paper is also susceptible to changes in the issuer’sfinancial condition or credit quality. In addition, under certaincircumstances commercial paper may become illiquid or maysuffer from reduced liquidity. Commercial paper is generallyunsecured, which increases the credit risk associated with thistype of investment.

DEBT EXTENSION RISK is the risk that an issuer will exercise itsright to pay principal on an obligation held by the Portfolio(such as an asset-backed security) later than expected. This mayhappen during a period of rising interest rates. Under thesecircumstances, the value of the obligation will decrease, and thePortfolio will suffer from the inability to invest in higheryielding securities.

U.S. GOVERNMENT SECURITIES RISK is the risk that the U.S.government will not provide financial support to its agencies,instrumentalities or sponsored enterprises if it is not obligatedto do so by law. Certain U.S. government securities purchasedby the Portfolio are neither issued nor guaranteed by the U.S.Treasury and, therefore, may not be backed by the full faith andcredit of the United States. It is possible that the issuers of suchsecurities will not have the funds to meet their paymentobligations in the future.

VARIABLE OR FLOATING RATE INSTRUMENTS RISK is the riskthat securities with variable or floating rates can be less sensitiveto interest rate changes than securities with fixed interest rates,but may decline in value and negatively impact the Portfolio,particularly if changes in prevailing interest rates are morefrequent or sudden than the rate changes for the variable orfloating rate securities, which only occur periodically. Althoughvariable and floating rate securities are less sensitive to interestrate risk than fixed-rate securities, they are subject to greaterliquidity risk, credit risk and default risk, which could impedetheir value.

LIQUIDITY RISK is the risk that the Portfolio will not be able topay redemption proceeds in a timely manner because ofunusual market conditions, an unusually high volume ofredemption requests, legal restrictions impairing its ability tosell particular securities at an advantageous market price orother reasons. Certain portfolio securities may be less liquid

than others, which may make them difficult or impossible tosell at the time and the price that the Portfolio would like andthe Portfolio may have to lower the price, sell other securitiesinstead or forgo an investment opportunity. In addition, lessliquid securities may be more difficult to value and marketsmay become less liquid when there are fewer interested buyersor sellers or when dealers are unwilling or unable to make amarket for certain securities. For these same reasons, less liquidsecurities that the Portfolio may want to invest in may bedifficult or impossible to purchase. Federal banking regulationsmay also cause certain dealers to reduce their inventories ofcertain securities, which may further decrease the Portfolio’sability to buy or sell such securities. All of these risks mayincrease during periods of market turmoil and could have anegative effect on the Portfolio’s performance.

MARKET RISK is the risk that the value of the Portfolio’sinvestments may increase or decrease in response to expected,real or perceived economic, political or financial events in theU.S. or global markets. The frequency and magnitude of suchchanges in value cannot be predicted. Certain securities andother investments held by the Portfolio may experienceincreased volatility, illiquidity, or other potentially adverseeffects in response to changing market conditions, inflation,changes in interest rates, lack of liquidity in the bond or equitymarkets, volatility in the equity markets, market disruptionscaused by local or regional events such as war, acts of terrorism,the spread of infectious illness (including epidemics andpandemics) or other public health issues, recessions or otherevents or adverse investor sentiment or other political,regulatory, economic and social developments, anddevelopments that impact specific economic sectors, industriesor segments of the market. These risks may be magnified ifcertain events or developments adversely interrupt the globalsupply chain; in these and other circumstances, such risksmight affect companies worldwide due to increasinglyinterconnected global economies and financial markets.

INCOME RISK is the risk that falling interest rates will cause thePortfolio’s income to decline. Income risk is generally higherfor short-term debt securities.

FINANCIAL SERVICES INDUSTRY RISK is the risk that, becausethe Portfolio will invest under normal market conditions atleast 25% of its total assets in the financial services industry, thePortfolio will be subject to greater risk of loss by economic,business, political or other developments which generally affectthis industry. Changes in government regulation and interestrates and economic downturns can have a significant negativeeffect on issuers in the financial services sector, including theprice of their securities or their ability to meet their paymentobligations.




ASSET-BACKED SECURITIES RISK. Asset-backed securitiesrepresent interests in pools of assets such as mortgages,commercial or consumer loans, or receivables and otherfinancial assets. Asset-backed securities are subject to credit,interest rate, prepayment, extension, valuation and liquidityrisk. These securities, in most cases, are not backed by the fullfaith and credit of the U.S. government and are subject to therisk of default on the underlying asset or loan, particularlyduring periods of economic downturn. Those asset-backedsecurities that are guaranteed as to the timely payment ofinterest and principal by a government entity, are notguaranteed as to market price, which will fluctuate. Smallmovements in interest rates (both increases and decreases) mayquickly and significantly reduce the value of certain asset-backed securities.

FOREIGN SECURITIES RISK is the risk that a foreign security,even if it is a U.S. dollar-denominated foreign security, couldlose value as a result of political, financial and economic eventsin foreign countries, tariffs and trade disputes, more or lessstringent foreign securities regulations and accounting anddisclosure standards or other factors. In addition, the Portfoliowill be subject to the risk that an issuer of foreign sovereigndebt or the government authorities that control the repaymentof the debt may be unable or unwilling to repay the principal orinterest when due.

CURRENCY RISK is the risk that foreign currencies, securitiesthat trade in or receive revenue in foreign currencies, orderivatives that provide exposure to foreign currencies willfluctuate in value relative to the U.S. dollar, adversely affectingthe value of the Portfolio’s investments and its returns. Becausethe Portfolio’s NAV is determined on the basis of U.S. dollars,you may lose money if the local currency of a foreign marketdepreciates against the U.S. dollar, even if the market value ofthe Portfolio’s holdings appreciates. In addition, fluctuations inthe exchange values of currencies could affect the economy orparticular business operations of companies in a geographicregion in which the Portfolio invests, causing an adverse impacton the Portfolio’s investments in the affected region.

MANAGEMENT RISK is the risk that a strategy used by thePortfolio’s investment adviser may fail to produce the intendedresults or that imperfections, errors or limitations in the toolsand data used by the investment adviser may cause unintendedresults.

FLOATING NAV RISK is the risk that because the share price ofthe Portfolio will fluctuate, when you sell your shares they maybe worth more or less than what you originally paid for them.

LIQUIDITY FEE AND REDEMPTION GATE RISK is the risk that thePortfolio may impose a “liquidity fee” (up to 2%) or“redemption gate” that temporarily restricts your ability to sell

shares for up to 10 business days if the Portfolio’s liquidity fallsbelow required minimums because of market conditions orother factors.

CYBERSECURITY RISK is the risk of an unauthorized breach andaccess to Portfolio assets, Portfolio or customer data (includingprivate shareholder information), or proprietary information,or the risk of an incident occurring that causes the Portfolio,the investment adviser, custodian, transfer agent, distributorand other service providers and financial intermediaries tosuffer data breaches, data corruption or lose operationalfunctionality or prevent Portfolio investors from purchasing,redeeming or exchanging shares or receiving distributions. ThePortfolio and its investment adviser have limited ability toprevent or mitigate cybersecurity incidents affecting third partyservice providers. Successful cyber-attacks or other cyber-failures or events affecting the Portfolio or its service providersmay adversely impact and cause financial losses to the Portfolioor its shareholders. Issuers of securities in which the Portfolioinvests are also subject to cybersecurity risks, and the value ofthese securities could decline if the issuers experience cyber-attacks or other cyber-failures.

You could lose money by investing in the Portfolio. Becausethe share price of the Portfolio will fluctuate, when you sellyour shares they may be worth more or less than what youoriginally paid for them. The Portfolio may impose a fee uponsale of your shares or may temporarily suspend your ability tosell shares if the Portfolio’s liquidity falls below requiredminimums because of market conditions or other factors. Aninvestment in the Portfolio is not a deposit of any bank and isnot insured or guaranteed by the Federal Deposit InsuranceCorporation, any other government agency, or The NorthernTrust Company, its affiliates, subsidiaries or any other bank.The Portfolio’s sponsor has no legal obligation to providefinancial support to the Portfolio, and you should not expectthat the sponsor will provide financial support to the Portfolioat any time.

P O R T F O L I O P E R F O R M A N C E

Williams Capital Shares of the Portfolio had not commencedoperations as of December 31, 2019 and, therefore, noperformance information for Williams Capital Shares isincluded in this Prospectus. The bar chart and table that followprovide an indication of the risks of investing in the Portfolioby showing changes in the performance from year to year ofShares, another class of shares of the Portfolio that is offered ina separate prospectus.

The Portfolio’s past performance is not necessarily anindication of how the Portfolio will perform in the future.




Updated performance information for the Portfolio isavailable and may be obtained on the Portfolio’s website atnortherntrust.com/institutional or by calling 800-637-1380.

CALENDAR YEAR TOTAL RETURN (SHARES)*†

0

1

2

3

2010 2011 2012 2013 2014 2015 2016 2017 2018 2019

0.15% 0.08% 0.08% 0.05% 0.02% 0.07%

0.49%

1.04%

1.99%

2.29%

* For the periods shown in the bar chart above, the highest quarterlyreturn was 0.63% in the first quarter of 2019, and the lowestquarterly return was 0.00% in the first quarter of 2014.

AVERAGE ANNUAL TOTAL RETURNS†

(For the periods ended December 31, 2019)

InceptionDate 1-Year 5-Year 10-Year

SinceInception

Shares 08/21/03 2.29% 1.17% 0.62% 1.44%

† The returns in the bar chart and table above are for Shares, anotherclass of shares of the Portfol io that is offered in a separateprospectus. Wil l iams Capital Shares would have substantial ly similarannual returns because Wil l iams Capital Shares are invested in thesame portfol io of securi t ies and the annual returns would dif fer onlyto the extent that the classes have dif ferent expenses.

The 7-day yield for Shares of the Portfol io as of December 31, 2019:1.72%. For the current 7-day yield call 800-637-1380 or visi tnortherntrust .com/inst i tut ional.

M A N A G E M E N T

INVESTMENT ADVISER. Northern Trust Investments, Inc.(“NTI”), an indirect subsidiary of Northern Trust Corporation,serves as the investment adviser of the Portfolio. The NorthernTrust Company, an affiliate of NTI, serves as transfer agent,custodian and sub-administrator to the Portfolio.

P U R C H A S E A N D S A L E O F P O R T F O L I O S H A R E S

Williams Capital Shares of the Portfolio are offered exclusivelyto clients of Siebert Williams Shank & Co., LLC (“SWS”).

You may purchase Williams Capital Shares of the Portfoliothrough an authorized intermediary generally with no

minimum initial investment. As of December 31, 2019, therewere no Williams Capital Shares outstanding for the Portfolio.

On any business day, you may sell (redeem) or exchangeWilliams Capital Shares of the Portfolio through yourinstitutional account by contacting your Northern Trustaccount representative or authorized intermediary. If youpurchase Williams Capital Shares of the Portfolio directly fromthe Trust, you may sell (redeem) or exchange your shares inone of the following ways:

▪ By Mail – Send a written request to: Northern InstitutionalFunds, P.O. Box 75986, Chicago, Illinois 60675-5986.

▪ By Telephone – Call the Northern Institutional Funds Centerat 800-637-1380 or the SWS dedicated phone line at866-926-3863 for instructions.

▪ By Wire – Authorize wire redemptions on your New AccountApplication and have proceeds sent by federal wire transfer toa previously designated bank account (the minimumredemption amount by this method is $10,000).

The Portfolio may impose a liquidity fee on redemptions (up to2%) or temporarily restrict redemptions from the Portfolio forup to 10 business days during a 90-day period (a redemptiongate), in the event that the Portfolio’s weekly liquid assets fallbelow the following thresholds:

▪ 30% weekly liquid assets—If the Portfolio’s weekly liquidassets fall below 30% of the Portfolio’s total assets as of theend of a business day, and the Board of Trustees determines itis in the best interests of the Portfolio, the Board may imposea liquidity fee of no more than 2% of the amount redeemedand/or a redemption gate that temporarily suspends the rightof redemption. Liquidity fees and/or redemption gates may beimplemented as early as the same business day that weeklyliquid assets of the Portfolio fall below 30% of the total assets.

▪ 10% weekly liquid assets—If the Portfolio’s weekly liquidassets fall below 10% of the Portfolio’s total assets as of theend of a business day, the Portfolio will impose, at thebeginning of the next business day, a liquidity fee of 1% of theamount redeemed, unless the Board determines thatimposing the fee would not be in the best interests of thePortfolio or determines that a lower or higher fee (not toexceed 2%) would be in the best interests of the Portfolio.

T A X I N F O R M A T I O N

The Portfolio will not maintain a stable share price and a sale ofPortfolio shares may result in a capital gain or loss for you.When you sell your shares, you will generally recognize acapital gain or loss in an amount equal to the differencebetween your adjusted tax basis in the shares and the amount




received, unless you adopt a simplified “NAV method” ofaccounting with respect to your shares. You are urged toconsult your tax professional regarding which method ofaccounting is appropriate for you. Any liquidity fees you incuron shares redeemed will generally decrease the amount of anycapital gain (or increase the amount of any capital loss) yourecognize with respect to such redemption. The Portfolio’sdistributions are generally taxable to you as ordinary income,capital gains, or a combination of the two, unless you areinvesting through a tax-exempt or tax-deferred arrangement,such as a 401(k) plan or an individual retirement account.Distributions may be taxable upon withdrawal fromtax-deferred accounts.

P A Y M E N T S T O B R O K E R S - D E A L E R S A N D O T H E R

F I N A N C I A L I N T E R M E D I A R I E S

If you purchase Williams Capital Shares of the Portfoliothrough a broker-dealer or other financial intermediary (suchas a bank), the Portfolio and its related companies may pay theintermediary for the sale of Williams Capital Shares of thePortfolio and related services. These payments may create aconflict of interest by influencing the broker-dealer or otherintermediary and your salesperson to recommend the Portfolioover another investment. Ask your salesperson or visit yourfinancial intermediary’s website for more information.



U . S . G O V E R N M E N T S E L E C T P O R T F O L I O

I N V E S T M E N T O B J E C T I V E

The Portfolio seeks to maximize current income to the extentconsistent with the preservation of capital and maintenance ofliquidity by investing exclusively in high quality money marketinstruments.

F E E S A N D E X P E N S E S O F T H E P O R T F O L I O

This table describes the fees and expenses that you may pay ifyou buy and hold Williams Capital Shares of the Portfolio.

Shareholder Fees (fees paid directly from your investment)

None

Annual Portfolio Operating Expenses (expenses that you pay each year asa percentage of the value of your investment)

WilliamsCapitalShares

Management Fees 0.18%

Other Expenses 0.03%

Transfer Agent Fees 0.02%

Service Fees None

Other Operating Expenses 0.01%

Total Annual Portfolio Operating Expenses 0.21%

Expense Reimbursement(1) (0.01)%

Total Annual Portfolio Operating Expenses After ExpenseReimbursement 0.20%

(1) Northern Trust Investments, Inc. has contractually agreed to reimburse a por-tion of the operating expenses of the Portfolio (other than certain exceptedexpenses, i.e., Acquired Fund Fees and Expenses, service fees, the compensa-tion paid to each Independent Trustee of the Trust, expenses of third partyconsultants engaged by the Board of Trustees, membership dues paid to theInvestment Company Institute and Mutual Fund Directors Forum, expenses inconnection with the negotiation and renewal of the revolving credit facility,extraordinary expenses and interest) to the extent the “Total Annual PortfolioOperating Expenses” exceed 0.20%. This contractual limitation may not beterminated before April 1, 2021 without the approval of the Board of Trustees.

E X A M P L E

The following Example is intended to help you compare thecost of investing in Williams Capital Shares of the Portfoliowith the cost of investing in other mutual funds. The Exampleassumes that you invest $10,000 in the Portfolio for the timeperiods indicated and then redeem all of your shares at the endof those periods. The Example also assumes that yourinvestment has a 5% return each year and that the Portfolio’soperating expenses remain the same. Although your actualcosts may be higher or lower, based on these assumptions yourcosts would be:

1 Year 3 Years 5 Years 10 Years

Williams Capital Shares $20 $67 $117 $267

P R I N C I P A L I N V E S T M E N T S T R A T E G I E S

The Portfolio seeks to achieve its objective by investing, undernormal circumstances, substantially all (and at least 99.5%) ofits total assets in cash, securities issued or guaranteed as toprincipal and interest by the U.S. government or by a personcontrolled or supervised by and acting as an instrumentality ofthe U.S. government pursuant to authority granted by theCongress of the United States or any certificate of deposit ofany of the foregoing, and repurchase agreements that are fullycollateralized by cash or such securities. Subject to theforegoing 99.5% investment strategy requirement, undernormal circumstances, the Portfolio will seek to invest at least50% of its net assets in the following securities that pay interestthat generally is exempt from state income taxation:

▪ U.S. Treasury bills;

▪ U.S. Treasury notes;

▪ U.S. Treasury STRIPS;

▪ securities issues by the Federal Home Loan Bank (FHLB);

▪ securities issues by the Federal Farm Credit Bank (FFCB); and

▪ securities issues by the Tennessee Valley Authority.

The Portfolio, under normal circumstances, will invest at least80% of its net assets (plus the amount of any borrowings forinvestment purposes) in U.S. government securities andrepurchase agreements collateralized solely by U.S. governmentsecurities.

The Portfolio operates as a “government money market fund”under Rule 2a-7 of the Investment Company Act of 1940, asamended. As a “government money market fund” underRule 2a-7, the Portfolio (1) is permitted to use the amortized costmethod of valuation to seek to maintain a stable net asset value




(“NAV”) of $1.00 share price, and (2) is not required to impose aliquidity fee and/or a redemption gate on Portfolio redemptionsthat might apply to other types of money market funds shouldcertain triggering events specified in Rule 2a-7 occur.

The Securities and Exchange Commission (“SEC”) imposesstrict requirements on the investment quality, maturity,diversification and liquidity of the Portfolio’s investments.Accordingly, the Portfolio’s investments must have a remainingmaturity of no more than 397 days and must be high quality.The Portfolio’s investment adviser may consider, among otherthings, credit, interest rate and prepayment risks as well asgeneral market conditions when deciding whether to buy or sellinvestments for the Portfolio.

P R I N C I P A L R I S K S

As with any investment, you could lose all or part of yourinvestment in the Portfolio, and the Portfolio’s performancecould trail that of other investments. The Portfolio is subject tocertain risks, including the principal risks noted below, any ofwhich may adversely affect the Portfolio’s NAV, trading price,yield, total return and ability to meet its investment objective.Each risk noted below is considered a principal risk of investingin the Portfolio, regardless of the order in which it appears. Thesignificance of each risk factor below may change over time andyou should review each risk factor carefully.

STABLE NAV RISK is the risk that the Portfolio will not be ableto maintain a NAV per share of $1.00 at all times. A significantenough market disruption or drop in market prices of securitiesheld by the Portfolio, especially at a time when the Portfolioneeds to sell securities to meet shareholder redemptionrequests, could cause the value of the Portfolio’s shares todecrease to a price less than $1.00 per share. If the Portfolio failsto maintain a stable NAV (or if there is a perceived threat ofsuch a failure), the Portfolio could be subject to increasedredemption activity, which could adversely affect its NAV.

INTEREST RATE RISK is the risk that during periods of risinginterest rates, the Portfolio’s yield (and the market value of itssecurities) will tend to be lower than prevailing market rates; inperiods of falling interest rates, the Portfolio’s yield (and themarket value of its securities) will tend to be higher. Securitieswith longer maturities tend to be more sensitive to changes ininterest rates, causing them to be more volatile than securitieswith shorter maturities. Securities with shorter maturities tendto provide lower returns and be less volatile than securities withlonger maturities. If interest rates rise, the Portfolio’s yield maynot increase proportionately, and the maturities of incomesecurities that have the ability to be prepaid or called by theissuer may be extended. Changing interest rates may haveunpredictable effects on the markets and the Portfolio’s

investments. Recent and any future declines in interest ratelevels could cause the Portfolio’s earnings to fall below thePortfolio’s expense ratio, resulting in a negative yield and adecline in the Portfolio’s share price. A general rise in interestrates may cause investors to move out of fixed incomesecurities on a large scale, which could adversely affect the priceand liquidity of fixed income securities and could also result inincreased redemptions for the Portfolio. Fluctuations in interestrates may also affect the liquidity of fixed income securities andinstruments held by the Portfolio.

CREDIT (OR DEFAULT) RISK is the risk that the inability orunwillingness of an issuer or guarantor of a fixed-incomesecurity, or a counterparty to a repurchase or other transaction,to meet its principal or interest payments or other financialobligations will adversely affect the value of the Portfolio’sinvestments and its returns. Changes in the credit rating of adebt security or of the issuer of a debt security held by thePortfolio could have a similar effect. The Portfolio could also bedelayed or hindered in its enforcement of rights against anissuer, guarantor or counterparty.

DEBT EXTENSION RISK is the risk that an issuer will exercise itsright to pay principal on an obligation held by the Portfolio(such as an asset-backed security) later than expected. This mayhappen during a period of rising interest rates. Under thesecircumstances, the value of the obligation will decrease and thePortfolio will suffer from the inability to invest in higheryielding securities.

PREPAYMENT (OR CALL) RISK is the risk that because manyissuers of fixed-income securities have an option to prepay theirfixed-income securities, the exercise of such option may resultin a decreased rate of return and a decline in value of thosesecurities and accordingly, a decline in the Portfolio’s NAV.Issuers may be more likely to prepay their securities if interestrates fall. If this happens, the Portfolio will not benefit from therise in the market price of the securities that normallyaccompanies a decline in interest rates, and will be forced toreinvest prepayment proceeds at a time when yield on securitiesavailable in the market are lower than the yield on prepaidsecurities. The Portfolio may also lose any premium it paid topurchase the securities.

VARIABLE OR FLOATING RATE INSTRUMENTS RISK is the risk thatsecurities with variable or floating rates can be less sensitive tointerest rate changes than securities with fixed interest rates, butmay decline in value and negatively impact the Portfolio,particularly if changes in prevailing interest rates are more frequentor sudden than the rate changes for the variable or floating ratesecurities, which only occur periodically. Although variable andfloating rate securities are less sensitive to interest rate risk thanfixed-rate securities, they are subject to greater liquidity risk, creditrisk and default risk, which could impede their value.




INCOME RISK is the risk that falling interest rates will cause thePortfolio’s income to decline. Income risk is generally higherfor short-term debt securities.

U.S. GOVERNMENT SECURITIES RISK is the risk that the U.S.government will not provide financial support to its agencies,instrumentalities or sponsored enterprises if it is not obligatedto do so by law. Certain U.S. government securities purchasedby the Portfolio are neither issued nor guaranteed by the U.S.Treasury and, therefore, may not be backed by the full faith andcredit of the United States. It is possible that the issuers of suchsecurities will not have the funds to meet their paymentobligations in the future.

MARKET RISK is the risk that the value of the Portfolio’sinvestments may increase or decrease in response to expected,real or perceived economic, political or financial events in theU.S. or global markets. The frequency and magnitude of suchchanges in value cannot be predicted. Certain securities andother investments held by the Portfolio may experienceincreased volatility, illiquidity, or other potentially adverseeffects in response to changing market conditions, inflation,changes in interest rates, lack of liquidity in the bond or equitymarkets, volatility in the equity markets, market disruptionscaused by local or regional events such as war, acts of terrorism,the spread of infectious illness (including epidemics andpandemics) or other public health issues, recessions or otherevents or adverse investor sentiment or other political,regulatory, economic and social developments, anddevelopments that impact specific economic sectors, industriesor segments of the market. These risks may be magnified ifcertain events or developments adversely interrupt the globalsupply chain; in these and other circumstances, such risksmight affect companies worldwide due to increasinglyinterconnected global economies and financial markets.

MANAGEMENT RISK is the risk that a strategy used by thePortfolio’s investment adviser may fail to produce the intendedresults or that imperfections, errors or limitations in the tools anddata used by the investment adviser may cause unintended results.

CYBERSECURITY RISK is the risk of an unauthorized breach andaccess to Portfolio assets, Portfolio or customer data (includingprivate shareholder information), or proprietary information,or the risk of an incident occurring that causes the Portfolio,the investment adviser, custodian, transfer agent, distributorand other service providers and financial intermediaries tosuffer data breaches, data corruption or lose operationalfunctionality or prevent Portfolio investors from purchasing,redeeming or exchanging shares or receiving distributions. ThePortfolio and its investment adviser have limited ability toprevent or mitigate cybersecurity incidents affecting third partyservice providers. Successful cyber-attacks or other cyber-failures or events affecting the Portfolio or its service providers

may adversely impact and cause financial losses to the Portfolioor its shareholders. Issuers of securities in which the Portfolioinvests are also subject to cybersecurity risks, and the value ofthese securities could decline if the issuers experience cyber-attacks or other cyber-failures.

LARGE SHAREHOLDER RISK is the risk that the Portfolio mayexperience adverse effects when certain large shareholders,including funds or accounts over which the Portfolio’sinvestment adviser or an affiliate of the investment adviser hasinvestment discretion, purchase or redeem large amounts ofshares of the Portfolio. Such large shareholder redemptions,which may occur rapidly and unexpectedly, may cause thePortfolio to sell its securities at times it would not otherwise doso, which may negatively impact its liquidity and/or NAV. Suchsales may also accelerate the increase of taxable income toshareholders if these sales result in gains, and may also increasetransaction costs. In addition, large redemptions could lead toan increase in the Portfolio’s expense ratio due to expensesbeing allocated over a smaller asset base. Large share purchasesof the Portfolio may adversely affect the Portfolio’sperformance to the extent that the Portfolio is delayed ininvesting or otherwise maintains a larger cash position than itordinarily would.

You could lose money by investing in the Portfolio. Althoughthe Portfolio seeks to preserve the value of your investment at$1.00 per share, the Portfolio cannot guarantee it will do so.An investment in the Portfolio is not a deposit of any bank andis not insured or guaranteed by the Federal Deposit InsuranceCorporation, any other government agency, or The NorthernTrust Company, its affiliates, subsidiaries or any other bank.The Portfolio’s sponsor has no legal obligation to providefinancial support to the Portfolio, and you should not expectthat the sponsor will provide financial support to the Portfolioat any time.

P O R T F O L I O P E R F O R M A N C E

The bar chart and table that follow provide an indication of therisks of investing in the Portfolio by showing the performanceof the Portfolio for a one year period and since inception.

The Portfolio’s past performance is not necessarily anindication of how the Portfolio will perform in the future.

Updated performance information for the Portfolio is availableand may be obtained on the Portfolio’s website atnortherntrust.com/institutional or by calling 800-637-1380.




CALENDAR YEAR TOTAL RETURN (WILLIAMS CAPITAL SHARES)*

0

2

1

3

2015 20172016 2018 2019

0.02%0.23%

0.73%

2.08%

1.68%

* For the periods shown in the bar chart above, the highest quarterlyreturn was 0.56% in the second quarter of 2019, and the lowestquarterly return was 0.00% in the third quarter of 2015.

AVERAGE ANNUAL TOTAL RETURNS(For the periods ended December 31, 2019)

InceptionDate 1-Year 5-Year

SinceInception

Williams Capital Shares 9/15/14 2.08% 0.94% 0.89%

The 7-day yield for Wil l iams Capital Shares of the Portfol io as ofDecember 31, 2019: 1.53%. For the current 7-day yield call800-637-1380 or vis i t northerntrust.com/inst i tut ional.

M A N A G E M E N T

INVESTMENT ADVISER. Northern Trust Investments, Inc.(“NTI”), an indirect subsidiary of Northern Trust Corporation,serves as the investment adviser of the Portfolio. The NorthernTrust Company, an affiliate of NTI, serves as transfer agent,custodian and sub-administrator to the Portfolio.

P U R C H A S E A N D S A L E O F P O R T F O L I O S H A R E S

Williams Capital Shares of the Portfolio are offered exclusivelyto clients of Siebert Williams Shank & Co., LLC (“SWS”).

You may purchase Williams Capital Shares of the Portfoliothrough an authorized intermediary generally with nominimum initial investment.

On any business day, you may sell (redeem) or exchangeWilliams Capital Shares of the Portfolio through yourinstitutional account by contacting your Northern Trustaccount representative or authorized intermediary. If youpurchase Williams Capital Shares of the Portfolio directly fromthe Trust, you may sell (redeem) or exchange your shares inone of the following ways:

▪ By Mail – Send a written request to: Northern InstitutionalFunds, P.O. Box 75986, Chicago, Illinois 60675-5986.

▪ By Telephone – Call the Northern Institutional Funds Centerat 800-637-1380 or the SWS dedicated phone line at866-926-3863 for instructions.

▪ By Wire – Authorize wire redemptions on your New AccountApplication and have proceeds sent by federal wire transfer toa previously designated bank account (the minimumredemption amount by this method is $10,000).

T A X I N F O R M A T I O N

The Portfolio’s distributions are generally taxable to you asordinary income, capital gains, or a combination of the two,unless you are investing through a tax-exempt or tax-deferredarrangement, such as a 401(k) plan or an individual retirementaccount. Distributions may be taxable upon withdrawal fromtax-deferred accounts.

P A Y M E N T S T O B R O K E R S - D E A L E R S A N D O T H E R

F I N A N C I A L I N T E R M E D I A R I E S

If you purchase Williams Capital Shares of the Portfoliothrough a broker-dealer or other financial intermediary (suchas a bank), the Portfolio and its related companies may pay theintermediary for the sale of Williams Capital Shares of thePortfolio and related services. These payments may create aconflict of interest by influencing the broker-dealer or otherintermediary and your salesperson to recommend the Portfolioover another investment. Ask your salesperson or visit yourfinancial intermediary’s website for more information.



I N V E S T M E N T A D V I S E R

This Prospectus describes two money market portfolios (each a“Portfolio” and collectively, the “Portfolios”), which arecurrently offered by Northern Institutional Funds (the“Trust”).

Northern Trust Investments, Inc. (“NTI” or the “InvestmentAdviser”), an indirect subsidiary of Northern TrustCorporation, serves as the Investment Adviser of the Portfoliosand is responsible for their overall administration. NTI islocated at 50 South LaSalle Street, Chicago, Illinois 60603.

NTI is an Illinois State Banking Corporation and an investmentadviser registered under the Investment Advisers Act of 1940, asamended. It primarily manages assets for institutional andindividual separately managed accounts, investment companiesand bank common and collective funds.

Northern Trust Corporation is regulated by the Board ofGovernors of the Federal Reserve System as a financial holdingcompany under the U.S. Bank Holding Company Act of 1956,as amended. Unless otherwise indicated, NTI and TheNorthern Trust Company (“TNTC”) are referred to collectivelyin this Prospectus as “Northern Trust.”

As of December 31, 2019, Northern Trust Corporation,through its affiliates, had assets under custody of $9.23 trillionand assets under investment management of $1.23 trillion.

Under the Management Agreement with the Trust, theInvestment Adviser, subject to the general supervision of theTrust’s Board of Trustees, is responsible for making investmentdecisions for the Portfolios and for placing purchase and saleorders for portfolio securities, as well as for providingadministration services to the Portfolios.



M A N A G E M E N T F E E S

As compensation for advisory services and administrationservices and the assumption of related expenses, NTI is entitledto a management fee, computed daily and payable monthly, atannual rates set forth in the table below (expressed as apercentage of each Portfolio’s respective average daily netassets). The table also reflects the management fees paid by eachof the Portfolio for the fiscal year ended November 30, 2019(expressed as a percentage of each Portfolio’s respective averagedaily net assets).

NTI has contractually agreed to reimburse a portion of theoperating expenses of each Portfolio (other than certain feesand expenses shown in the table under the caption “Fees andExpenses of the Portfolio” in each Portfolio’s PortfolioSummary) so that “Total Annual Portfolio Operating ExpensesAfter Expense Reimbursement” do not exceed the amountshown in the footnote to the table under the caption “Fees andExpenses of the Portfolio” in each Portfolio Summary. The“Total Annual Portfolio Operating Expenses After ExpenseReimbursement” for the Portfolios may be higher than thecontractual limitation for the Portfolios as a result of certainexcepted expenses that are not reimbursed. The contractualexpense reimbursement arrangement is expected to continue

until at least April 1, 2021. The contractual expensereimbursement arrangement will continue automaticallythereafter for periods of one year (each such one-year period, a“Renewal Year”). The arrangement may be terminated, as toany succeeding Renewal Year, by NTI or a Portfolio upon 60days’ written notice prior to the end of the current RenewalYear. The Board of Trustees may terminate the arrangement atany time with respect to a Portfolio if it determines that it is inthe best interest of the Portfolio and its shareholders.

NTI may reimburse additional expenses or waive all or aportion of the management fees of the Portfolios from time totime, including to avoid a negative yield. Any such additionalexpense reimbursement or fee waiver would be voluntary andcould be implemented, increased or decreased, or discontinuedat any time. There is no guarantee that a Portfolio will be ableto avoid a negative yield.

A discussion regarding the Board of Trustees’ basis for its mostrecent approval of the Portfolios’ Management Agreement isavailable in the Portfolios’ semi-annual report to shareholdersfor the six-month period ended May 31, 2019.

Contractual Management Fee RateManagement Fees Paid

for Fiscal Year Ended 11/30/19

PRIME OBLIGATIONS PORTFOLIO 0.13% 0.13%

U.S. GOVERNMENT SELECT PORTFOLIO 0.18% 0.18%



O T H E R P O R T F O L I O S E R V I C E S

TNTC serves as Transfer Agent and Custodian for eachPortfolio. The Transfer Agent performs various shareholderservicing functions, and any shareholder inquiries should bedirected to it. TNTC also performs certain administrativeservices for the Portfolios pursuant to a sub-administrationagreement with NTI. NTI pays TNTC for itssub-administration services out of its management fees, whichdo not represent additional expenses to the Portfolios.

TNTC, as Transfer Agent, is entitled to transfer agent fees at anannual rate of 0.015% of the average daily net assets of eachPortfolio. TNTC, as Custodian, receives an amount based on apre-determined schedule of charges approved by the Trust’s

Board of Trustees. TNTC, NTI and other Northern Trustaffiliates may provide other services to the Portfolios andreceive compensation for such services if consistent with theInvestment Company Act of 1940, as amended (the “1940 Act”)and the rules, exemptive orders and no-action letters issued bythe SEC thereunder. Unless required, investors in a Portfoliomay or may not receive specific notice of such additionalservices and fees.

Shares of the Trust are distributed by Northern FundsDistributors, LLC (“NFD”), Three Canal Plaza, Suite 100,Portland, Maine, 04101. NFD is not affiliated with TNTC, NTIor any other Northern Trust affiliate.



P U R C H A S I N G A N D S E L L I N G W I L L I A M S C A P I T A L S H A R E S

THE TRUST OFFERS TWO MONEY MARKET PORTFOLIOS TO INSTITUTIONAL INVESTORS IN THIS

PROSPECTUS

The descriptions in the Portfolio Summaries may help youdecide whether a Portfolio fits your investment needs. Keep inmind, however, that no guarantee can be made that a Portfoliowill meet its investment objective and no Portfolio should berelied upon as a complete investment program.

I N V E S T O R S

Williams Capital Shares of the Portfolios are offeredexclusively to clients of Siebert Williams Shank & Co., LLC(“SWS”).

There is no sales charge imposed on investments.

S H A R E C L A S S E S

Each Portfolio is authorized to offer four classes of shares(Shares, Service Shares, Premier Shares and Williams CapitalShares). Shares, Service Shares and Premier Shares aredescribed in separate prospectuses.

▪ Williams Capital Shares bear their pro rata portion of alloperating expenses paid by a Portfolio, except for transferagent fees.

Please note that the fee and expense information shown under“Fees and Expenses of the Portfolio” in the PortfolioSummaries beginning on page 3 does not reflect any charges(such as allocation or account maintenance fees) that may beimposed by TNTC, its affiliates and SWS on their clients. (Formore information, please see “Account Policies and OtherInformation—Financial Intermediaries” on page 23.)

P U R C H A S I N G W I L L I A M S C A P I T A L S H A R E S

You may purchase Williams Capital Shares of each Portfoliothrough an authorized intermediary generally with nominimum initial investment.

O P E N I N G A N A C C O U N T

THROUGH AN INSTITUTIONAL ACCOUNT. If you are openingan institutional account at Northern Trust, a Northern Trustrepresentative can assist you with all phases of yourinvestment. To purchase shares through your account, contactyour Northern Trust representative for further information.

THROUGH AN AUTHORIZED INTERMEDIARY. The Trust hasauthorized certain Institutions acting as financialintermediaries (including banks, trust companies, brokers andinvestment advisers) to accept purchase orders from theircustomers on behalf of the Portfolios. See “Account Policiesand Other Information—Financial Intermediaries” beginningon page 23 for additional information regarding purchases ofWilliams Capital Shares of a Portfolio through authorizedintermediaries.

DIRECTLY FROM THE TRUST. SWS clients may open ashareholder account and purchase shares directly from theTrust as described above under “Purchasing Shares”.

For your convenience, there are a number of ways to investdirectly in the Portfolios:

BY MAIL

▪ Read this Prospectus carefully.

▪ Complete and sign the New Account Application.

▪ Include acceptable evidence of authority (if applicable).

▪ Enclose a check or Federal Reserve draft payable to NorthernInstitutional Funds.

▪ Mail your check, acceptable evidence of authority (ifapplicable) and completed New Account Application to:

Northern Institutional FundsP.O. Box 75986Chicago, Illinois 60675-5986

▪ Additional documentation may be required to fulfill therequirements of the “Customer Identification Program”described beginning on page 22.

All checks must be payable in U.S. dollars and drawn on abank located in the United States. Cash and third party checksare not acceptable.

▪ For overnight delivery, use the following address:

Northern Institutional Fundsc/o The Northern Trust Company333 South Wabash AveChicago, Illinois 60604



B Y T E L E P H O N E

▪ Read this Prospectus carefully.

▪ Call the Northern Institutional Funds Center at 800-637-1380or the SWS dedicated phone line at 866-926-3863.

TO OPEN A NEW ACCOUNT PLEASE PROVIDE:

▪ The name of the Portfolio in which you would like to invest

▪ The number of shares or dollar amount to be invested

▪ The method of payment

TO ADD TO AN EXISTING ACCOUNT, PLEASE PROVIDE:

▪ The Institution’s name

▪ Your account number

B Y W I R E O R A U T O M A T E D C L E A R I N G H O U S E ( “ A C H ” )

T R A N S F E R

TO OPEN A NEW ACCOUNT:

▪ For more information or instructions regarding the purchaseof shares, call the Northern Institutional Funds Center at800-637-1380 or the SWS dedicated phone line at866-926-3863.

TO ADD TO AN EXISTING ACCOUNT:

▪ Have your bank wire federal funds or effect an ACH transferto:

The Northern Trust CompanyChicago, IllinoisABA Routing No. 0710-00152(Reference 10-Digit Portfolio account number, with no spaces(e.g., ##########))(Reference Shareholder’s Name)

S E L L I N G W I L L I A M S C A P I T A L S H A R E S

THROUGH AN INSTITUTIONAL ACCOUNT. You may sell(redeem) shares through your institutional account bycontacting your Northern Trust account representative.

THROUGH AN AUTHORIZED INTERMEDIARY. If you purchasedshares from an authorized intermediary, you may sell (redeem)shares by contacting your financial intermediary. See “AccountPolicies and Other Information—Financial Intermediaries”on page 23 for additional information regarding sales(redemptions) of Williams Capital Shares of a Portfoliothrough authorized intermediaries.

DIRECTLY THROUGH THE TRUST. SWS clients that purchaseshares directly from the Trust may redeem their shares throughthe Transfer Agent in one of the following ways:

B Y M A I L

SEND A WRITTEN REQUEST TO:


THE LETTER OF INSTRUCTION MUST INCLUDE:

▪ The signature of a duly authorized person (A signatureguarantee from an institution participating in the StockTransfer Agency Medallion Program (“STAMP”) also may berequired.)

▪ Your account number

▪ The name of the Portfolio

▪ The number of shares or the dollar amount to be redeemed

B Y T E L E P H O N E

▪ Call the Northern Institutional Funds Center at 800-637-1380or the SWS dedicated phone line at 866-926-3863 forinstructions.

▪ During periods of unusual economic or market activity,telephone redemptions may be difficult to implement. In suchevent, shareholders should follow the procedures outlinedabove under “Selling Williams Capital Shares—By Mail.”

B Y W I R E

If you authorize wire redemptions on your New AccountApplication, you can redeem shares and have the proceeds sentby federal wire transfer to a previously designated bankaccount.

▪ Call the Northern Institutional Funds Center at 800-637-1380or the SWS dedicated phone line at 866-926-3863 forinstructions.

▪ The minimum amount that may be redeemed by this methodis $10,000.



L I Q U I D I T Y F E E S A N D R E D E M P T I O N G A T E S — P R I M E

O B L I G A T I O N S P O R T F O L I O

The Prime Obligations Portfolio may impose a liquidity fee ofup to 2% on redemptions from the Portfolio or temporarilyrestrict redemptions from the Portfolio for up to 10 businessdays in any given 90-day period (a “redemption gate”) in theevent that the Portfolio’s weekly liquid assets fall below thefollowing thresholds:

30% weekly liquid assets – If the Portfolio’s weekly liquid assetsfall below 30% of the Portfolio’s total assets as of the end of abusiness day, and the Board determines it is in the best interestsof the Portfolio, the Board may impose a liquidity fee of nomore than 2% of the amount redeemed and/or a redemptiongate that temporarily suspends the right of redemption.Liquidity fees and/or redemption gates may be implemented asearly as the same business day that weekly liquid assets of thePortfolio fall below 30% of the total assets.

10% weekly liquid assets – If the Portfolio’s weekly liquid assetsfall below 10% of the Portfolio’s total assets as of the end of abusiness day, the Portfolio will impose, at the beginning of thenext business day, a liquidity fee of 1% of the amountredeemed, unless the Board determines that imposing the feewould not be in the best interests of the Portfolio or determinesthat a lower or higher fee (not to exceed 2%) would be in thebest interests of the Portfolio.

If the Board imposes a redemption gate, the Portfolio and thePortfolio’s authorized intermediaries will not acceptredemption orders until the Portfolio has notified shareholdersthat the redemption gate has been lifted. Any redemptionorders submitted while a redemption gate is in effect will be

cancelled without further notice. If you still wish to redeemshares once the redemption gate has been lifted, you will needto submit a new redemption request to the Portfolio or thePortfolio’s authorized intermediaries.

Liquidity fees and redemption gates may be terminated at anytime at the discretion of the Board. In addition, liquidity feesand redemption gates will terminate at the beginning of thenext business day once the Portfolio has invested 30% or moreof its total assets in weekly liquid assets. The Portfolio may onlysuspend redemptions for up to 10 business days in any 90-dayperiod.

Liquidity fees would generally be used to assist the Portfolio tostem redemptions during times of market stress.

A liquidity fee imposed by the Portfolio will reduce the amountyou will receive upon the redemption of your shares, and willgenerally decrease the amount of any capital gain or increasethe amount of any capital loss you will recognize with respect tothe redemption.

Any announcement regarding the imposition of a liquidity feeor redemption gate, or the termination of a liquidity fee or aredemption gate, will be available at the Portfolio’s website,northerntrust.com/institutional, and will be filed with the SECon Form N-CR.

If the Portfolio’s weekly liquid assets fall below 10% of thePortfolio’s total assets, the Portfolio reserves the right topermanently suspend redemptions and liquidate if the Board ofTrustees determines that it is not in the best interests of thePortfolio to continue operating.

Additional information regarding redemption fees and gates isincluded in the Statement of Additional Information (“SAI”).



A C C O U N T P O L I C I E S A N D O T H E R I N F O R M A T I O N

PURCHASE AND REDEMPTION MINIMUMS. There is generallyno minimum initial investment for Williams Capital Shares ofthe investment portfolios of the Trust when purchasing sharesthrough an authorized intermediary. A $10,000 minimumapplies for redemptions by wire. The Trust reserves the right towaive redemption minimums and to determine the manner inwhich a minimum is satisfied.

CALCULATING SHARE PRICE. The Trust issues and redeemsWilliams Capital Shares at NAV. The NAV for Williams CapitalShares of a Portfolio is calculated by dividing the value of thePortfolio’s net assets attributed to Williams Capital Shares bythe number of the Portfolio’s outstanding Williams CapitalShares. For Williams Capital Shares of the Prime ObligationsPortfolio, the NAV is calculated on each Business day as of2:00 p.m. Central time. For Williams Capital Shares of U.S.Government Select Portfolio, the NAV is calculated on eachBusiness Day as of 4:00 p.m. Central time. Portfolio shares maybe priced on days when the New York Stock Exchange (the“Exchange”) is closed if the Securities Industry and FinancialMarkets Association (“SIFMA”) recommends that the bondmarkets remain open for all or part of the day or on days whenthe Federal Reserve Bank of New York (the “New York Fed”) isopen. The NAV used in determining the price of your shares isthe one calculated after your purchase, exchange or redemptionorder is received in good order as described on page 22.

The Prime Obligations Portfolio is required to price andtransact in its shares at a floating NAV, rounded to the fourthdecimal place (e.g., $1.0000). Investments of the PrimeObligations Portfolio for which market quotations are readilyavailable will be valued using last available bid prices or currentmarket quotations provided by dealers or prices (includingevaluated prices) supplied by the Portfolio’s approvedindependent third-party pricing services, each in accordancewith valuation procedures approved by the Board of Trustees.If market quotations are not readily available, or if it is believedthat such quotations do not accurately reflect fair value, thevalue of the Portfolio’s investments may be otherwisedetermined in good faith by NTI under procedures establishedby the Board of Trustees. Circumstances in which securitiesmay be fair valued include periods when trading in a security issuspended, the exchange or market on which a security tradescloses early, the trading volume in a security is limited,corporate actions and announcements take place, or regulatorynews is released such as governmental approvals. Additionally,the Trust, in its discretion, may make adjustments to the pricesof securities held by the Portfolio if an event occurs after thepublication of market values normally used by the Portfolio butbefore the time as of which the Portfolio calculates its NAV,depending on the nature and significance of the event,consistent with applicable regulatory guidance and the Trust’sfair value procedures. The use of fair valuation involves the risk

that the values used by the Portfolio to price its investmentsmay be higher or lower than the values used by otherunaffiliated investment companies and investors to price thesame investments. Short-term obligations, which are debtinstruments with a maturity of 60 days or less, held by thePortfolios are valued at their amortized cost, which, accordingto the Investment Adviser, approximates fair value.

The U.S. Government Select Portfolio seeks to maintain a stableNAV of $1.00 per share by valuing the obligations held by it atamortized cost in accordance with SEC regulations. Amortizedcost will normally approximate fair value.

TIMING OF PURCHASE REQUESTS. Purchase requests received ingood order and accepted by the Transfer Agent or otherauthorized intermediary on any Business Day by 2:00 p.m.Central time with respect to the Prime Obligations Portfolio,and by 4:00 p.m. Central time with respect to the U.S.Government Select Portfolio, will be executed the day they arereceived by either the Transfer Agent or other authorizedintermediary at that day’s closing share price for the applicablePortfolio(s), provided that one of the following occurs:

▪ The Transfer Agent receives the payment in federal or otherimmediately available funds on the same Business Day by2:00 p.m. Central time with respect to the Prime ObligationsPortfolio and by the close of the Federal Reserve wire transfersystem (normally, 5:00 p.m. Central time) with respect to theU.S. Government Select Portfolio;

▪ The requests are placed by a financial or authorizedintermediary that has entered into a servicing agreement orother agreement with the Trust or its agent and payment infederal or other immediately available funds is received by theTransfer Agent by the close of the same Business Day inaccordance with the terms of the Trust’s or its agent’sagreement with the intermediary;

▪ Payment in federal or other immediately available funds isreceived by the close of the same Business Day in aninstitutional account maintained with Northern Trust or anaffiliate; or

▪ The purchase requests are placed through TNTC’s electronicfund trading platform and payment in federal or otherimmediately available funds is received by the Transfer Agentby the close of the Federal Reserve wire transfer system(normally, 5:00 p.m. Central time).

Purchase requests received in good order by the Transfer Agentor other authorized intermediary on a non-Business Day orafter the deadlines described above on a Business Day will beexecuted on the next Business Day, at that day’s closing shareprice for the applicable Portfolio(s), provided that payment ismade as noted above.



IN-KIND PURCHASES AND REDEMPTIONS. The Trust reservesthe right to accept payment for Williams Capital Shares in theform of securities that are permissible investments for aPortfolio. The Trust also reserves the right to pay redemptionsby a distribution “in-kind” of securities (instead of cash) from aPortfolio. See the SAI for further information about the termsof these purchases and redemptions.

MISCELLANEOUS PURCHASE INFORMATION.

▪ SWS clients are responsible for transmitting purchase ordersand delivering required funds on a timely basis.

▪ SWS clients are responsible for all losses and expenses of aPortfolio, and purchase orders may be cancelled, in the eventof any failure to make payment according to the proceduresoutlined in this Prospectus. In addition, a $20 charge will beimposed if a check does not clear.

▪ Exchanges into the Portfolios from another investmentportfolio in the Trust may be subject to any redemption feeimposed by the other investment portfolio.

▪ Williams Capital Shares of a Portfolio are entitled to thedividends declared by the Portfolio beginning on the BusinessDay the purchase order is executed, provided payment infederal or other immediately available funds is received by theTransfer Agent by the time designated in “Timing of PurchaseRequests” on page 19.

▪ The Trust, its agents and NFD each reserves the right, in theTrust’s sole discretion, to reject or restrict any purchase orderor exchange order, in whole or in part, for any reason. TheTrust also reserves the right to change or discontinue any ofits purchase procedures.

▪ The Trust, its agents and NFD each reserves the right tosuspend the offering of shares of a Portfolio when, in thejudgment of management, such suspension is in the bestinterests of the Portfolio.

▪ In certain circumstances, the Trust may advance the time bywhich purchase orders must be received. See “Early Closings”on page 22.

▪ If the Transfer Agent cannot locate an investor for a period oftime specified by appropriate state law, the investor’s accountmay be deemed legally abandoned and then escheated(transferred) to such state’s unclaimed property administratorin accordance with statutory requirements.

TIMING OF REDEMPTION AND EXCHANGE REQUESTS.

Redemption and exchange requests received in good order bythe Transfer Agent on any Business Day by 2:00 p.m. Centraltime with respect to the Prime Obligations Portfolio, end by4:00 p.m. Central time with respect to the U.S. GovernmentSelect Portfolio, will be executed on the same day at that day’sclosing share price for the applicable Portfolio.

Redemption and exchange requests received in good order bythe Transfer Agent or other authorized intermediary on anon-Business Day or after the deadline described above on aBusiness Day will be executed the next Business Day at thatday’s closing share price for the applicable Portfolio.

PAYMENT OF REDEMPTION PROCEEDS. If your account is helddirectly with a Portfolio, it is expected that the Portfolio willtypically pay out redemption proceeds to shareholders by thenext Business Day following a receipt of a redemption request.

If your account is held through an intermediary, the length oftime to pay redemption proceeds typically depends, in part, onthe terms of the agreement in place between the intermediaryand a Portfolio. For redemption proceeds that are paid eitherdirectly to you from a Portfolio or to your intermediary fortransmittal to you, it is expected that payments will typically bemade by wire, by ACH or by issuing check by the next BusinessDay following receipt of a redemption request in good orderfrom the intermediary by a Portfolio. Redemption requests thatare processed through investment professionals that utilize theNational Securities Clearing Corporation will generally settleone to three Business Days following receipt of a redemptionrequest in good order.

However, if you have recently purchased shares with a check orthrough an electronic transaction, payment may be delayed asdiscussed below under “Miscellaneous RedemptionInformation.”

It is expected that payment of redemption proceeds willnormally be made from uninvested cash or short-terminvestments, proceeds from the sale of portfolio securities, orborrowing through the Trust’s committed, unsecured creditfacility (see “Credit Facility and Borrowing,” on page 28). It ispossible that stressed market conditions or large shareholderredemptions may result in the need for utilization of aPortfolio’s ability to redeem in-kind in order to meetshareholder redemption requests. A Portfolio reserves the rightto pay all or part of your redemption proceeds in readilymarketable securities instead of cash (redemption in-kind).Redemption in-kind proceeds will typically be made bydelivering the selected securities to the redeeming shareholderwithin seven days after the receipt of the redemption request ingood order by a Portfolio.

MISCELLANEOUS REDEMPTION INFORMATION. All redemptionproceeds will be sent by check unless the Transfer Agent isdirected otherwise. Redemption proceeds also may be wired.Redemptions are subject to the following restrictions:

▪ The Board may impose a liquidity fee of up to 2% onredemptions from the Prime Obligations Portfolio ortemporarily restrict redemptions from the Portfolio for up to



10 business days in any given 90 day period. See “LiquidityFees and Redemption Gates—Prime Obligations Portfolio”beginning on page 18.

▪ The Trust reserves the right to defer crediting, sending orwiring redemption proceeds for up to 7 days (or such longerperiod permitted by the SEC) after receiving the redemptionorder if, in its judgment, an earlier payment could adverselyaffect a Portfolio. The processing of redemptions may besuspended, and the delivery of redemption proceeds may bedelayed beyond seven days, depending on the circumstances,for any period: (i) during which the Exchange is closed (otherthan on holidays or weekends), or during which trading onthe Exchange is restricted; (ii) when an emergency exists thatmakes the disposal of securities owned by a Portfolio or thedetermination of the fair value of a Portfolio’s net assets notreasonably practicable; or (iii) as permitted by order of theSEC for the protection of Portfolio shareholders.

▪ If you are redeeming Williams Capital Shares recentlypurchased by check or electronic transaction, yourredemption request may not be paid until your check orelectronic transaction has cleared. This may delay yourpayment for up to 10 days.

▪ Redemption requests made to the Transfer Agent by mailmust be signed by a person authorized by acceptabledocumentation on file with the Transfer Agent.

▪ Dividends on Williams Capital Shares are earned through andincluding the day prior to the day on which they areredeemed.

▪ SWS clients are responsible for transmitting redemptionorders.

▪ Subject to applicable law, the Trust and the Transfer Agentreserve the right to redeem shares held by any shareholderwho provides incorrect or incomplete account information orwhen such involuntary redemptions are necessary to avoidadverse consequences to the Trust and its shareholders or theTransfer Agent.

▪ Subject to applicable law, the Trust, Northern Trust and theiragents reserve the right to involuntarily redeem or suspend anaccount at a Portfolio’s then current NAV, in cases ofdisruptive conduct, suspected fraudulent or illegal activity,inability to verify the identity of an investor, or othercircumstances determined by the Trust and Northern Trust tobe in the best interest of the Trust and its shareholders.

▪ The Trust, Northern Trust and their agents reserve the right,without notice, to freeze any account and/or suspend accountservices when: (i) notice has been received of a disputeregarding the assets in an account, or a legal claim against anaccount; (ii) upon initial notification to Northern Trust of a

shareholder’s or authorized agent’s death until NorthernTrust receives required documentation in correct form; or(iii) if there is reason to believe a fraudulent transaction mayoccur or has occurred.

▪ The Trust may require any information from the shareholderreasonably necessary to ensure that a redemption request hasbeen duly authorized.

▪ The Trust reserves the right to change or discontinue any ofits redemption procedures.

▪ The Trust does not permit redemption proceeds to be sent byoutgoing International ACH Transaction (“IAT”). An IAT is apayment transaction involving a financial institution’s officelocated outside U.S. territorial jurisdiction.

▪ In certain circumstances, the Trust may advance the time bywhich redemption and exchange orders must be received. See“Early Closings” on page 22.

EXCHANGE PRIVILEGES. SWS clients (to the extent permitted bytheir account agreements) may exchange Williams CapitalShares of a Portfolio for the Williams Capital Shares of anotherinvestment portfolio of the Trust only if the registration of bothaccounts is identical. Both accounts must have the sameowner’s name and title, if applicable. A $1,000 minimumapplies to exchanges. An exchange is a redemption of WilliamsCapital Shares of one Portfolio and the purchase of WilliamsCapital Shares of another Portfolio. If the Williams CapitalShares redeemed are held in a taxable account, an exchange isconsidered a taxable event and may result in a gain or loss. TheTrust reserves the right to waive or modify minimuminvestment requirements in connection with exchanges. Withrespect to the Prime Obligations Portfolio, exchanges may besubject to liquidity fees and redemption gates. See “LiquidityFees and Redemption Gates—Prime Obligations Portfolio”beginning on page 18.

The Trust reserves the right to change or discontinue theexchange privilege at any time upon 60 days’ written notice toshareholders and to reject any exchange request. Exchanges areonly available in states where an exchange can legally be made.Before making an exchange, you should read the Prospectus forthe Williams Capital Shares you are acquiring.

EXCESSIVE TRADING IN PORTFOLIO SHARES. The Board ofTrustees of the Trust has not adopted, on behalf of thePortfolios, policies and procedures with respect to frequentpurchases and redemptions of Portfolio shares in light of thenature and high quality of the Portfolios’ investments. EachPortfolio reserves the right to refuse a purchase order ifmanagement of the Portfolio determines that the purchase maynot be in the best interests of the Portfolio.



TELEPHONE TRANSACTIONS. All calls may be recorded ormonitored. The Transfer Agent has adopted procedures in aneffort to establish reasonable safeguards against fraudulenttelephone transactions. If reasonable measures are taken toverify that telephone instructions are genuine, the Trust and itsservice providers will not be responsible for any loss resultingfrom fraudulent or unauthorized instructions received over thetelephone. In these circumstances, shareholders will bear therisk of loss. During periods of unusual market activity, you mayhave trouble placing a request by telephone. In this event,consider sending your request in writing by following theprocedures outlined above under “Purchasing and SellingWilliams Capital Shares—Selling Williams Capital Shares—ByMail.”

The proceeds of redemption orders received by telephone willbe sent by check, wire or transfer according to properinstructions. All checks will be made payable to the shareholderof record and mailed only to the shareholder’s address ofrecord.

The Trust reserves the right to refuse a telephone redemption,subject to applicable law.

ADVANCE NOTIFICATION OF LARGE TRANSACTIONS. The Trustrequests that an SWS client give advance notice to the TransferAgent by 11:00 a.m. Central time if it intends to place a purchaseor redemption order of $5 million or more on a Business Day.For other large purchase or redemption orders below $5 million,the Trust requests that SWS clients give advance notice to theTransfer Agent as early as possible in the day.

MAKING CHANGES TO YOUR ACCOUNT INFORMATION. Youmay make changes to wiring instructions only in writing. Youmay make changes to an address of record or certain otheraccount information in writing or by telephone. Writteninstructions must be accompanied by acceptable evidence ofauthority (if applicable). A signature guarantee also may berequired from an institution participating in STAMP.Additional requirements may be imposed. In accordance withSEC regulations, the Trust and Transfer Agent may charge ashareholder reasonable costs in locating a shareholder’s currentaddress.

SIGNATURE GUARANTEES. If a signature guarantee is required,it must be from an institution participating in STAMP, or otheracceptable evidence of authority (if applicable) must beprovided. Additional requirements may be imposed by theTrust. In addition to the situations described in this Prospectus,the Trust may require signature guarantees in othercircumstances based on the amount of a redemption request orother factors.

BUSINESS DAY. A “Business Day” is each Monday throughFriday that the New York Fed is open for business, except as

noted below. The New York Fed is closed on the followingnational holidays: New Year’s Day, Martin Luther King, Jr. Day,Presidents’ Day, Memorial Day, Independence Day, Labor Day,Columbus Day, Veterans Day, Thanksgiving Day and ChristmasDay. The Portfolios may also close on days when the New YorkFed is open but the Exchange is closed, such as Good Friday.

GOOD ORDER. A purchase, redemption or exchange request isconsidered to be “in good order” when all necessaryinformation is provided and all required documents areproperly completed, signed and delivered, including acceptableevidence of authority (if applicable). Additionally, a purchaseorder initiating the opening of an account will not beconsidered to be “in good order” unless the investor hasprovided all information required by the Trust’s “CustomerIdentification Program” described below.

CUSTOMER IDENTIFICATION PROGRAM. Federal law requiresthe Trust to obtain, verify and record identifying information,which may include the name, business street address, taxpayeridentification number or other identifying information for eachinvestor who opens or reopens an account with the Trust.Applications without this information, or without anindication that a taxpayer identification number has beenapplied for, may not be accepted. After acceptance, to theextent permitted by applicable law or the Trust’s customeridentification program, the Trust reserves the right to: (a) placelimits on account transactions until an investor’s identity isverified; (b) refuse an investment in the Trust; or(c) involuntarily redeem an investor’s shares and close anaccount in the event that an investor’s identity is not verified.The Trust and its agents will not be responsible for any loss inan investor’s account resulting from an investor’s delay inproviding all required identifying information or from closingan account and redeeming an investor’s shares when aninvestor’s identity is not verified.

EARLY CLOSINGS. The Portfolios reserve the right to advancethe time for accepting purchase, redemption or exchangeorders for same Business Day credit when the Exchange and/orthe bond market close early, trading on the Exchange isrestricted, an emergency arises or as otherwise permitted by theSEC. In addition, on any Business Day when SIFMArecommends that the bond markets close early, each Portfolioreserves the right to close at or prior to the SIFMArecommended closing time. If a Portfolio does so, it will ceasegranting same Business Day credit for purchase andredemption orders received at the Portfolio’s closing time andcredit will be given on the next Business Day. In addition, theBoard of Trustees of the Trust also may, for any Business Day,decide to change the time as of which a Portfolio’s NAV iscalculated in response to new developments such as alteredtrading hours, or as otherwise permitted by the SEC.



EMERGENCY OR UNUSUAL EVENTS. In the event the Exchangedoes not open for business because of an emergency or unusualevent, the Trust may, but is not required to, open one or morePortfolios for purchase, redemption and exchange transactionsif the Federal Reserve wire payment system is open. To learnwhether a Portfolio is open for business during an emergencysituation or unusual event, please call 800-637-1380 or visitnortherntrust.com/institutional.

FINANCIAL INTERMEDIARIES. The Trust has authorized SWS toaccept purchase, redemption and exchange orders from theirclients on behalf of the Portfolios. SWS also may designateother intermediaries to accept such orders, if approved by theTrust. A Portfolio will be deemed to have received an orderwhen the order is accepted by the authorized intermediary, andthe order will be priced at the Portfolio’s per share NAV nextdetermined, provided that the authorized intermediaryforwards the order (and payment for any purchase order) to theTransfer Agent on behalf of the Trust within agreed-upon timeperiods. If the order (or payment for any purchase order) is notreceived by the Transfer Agent within such time periods, theauthorized intermediary may be liable for fees and losses andthe transaction may be cancelled.

Northern Trust has entered into an agreement with SWSwhereby it will compensate SWS for services provided tobeneficial owners of Williams Capital Shares. The additionalcompensation and payments will be paid by Northern Trust orits affiliates and will not represent an additional expense to theTrust or its shareholders. Such payments may provideincentives for SWS to make shares of the Portfolios available toits clients, and may allow the Portfolios greater access to SWSand its clients than would be the case if no payments were paid.

SWS clients should read their account agreements with SWScarefully. SWS’s requirements may differ from those listed inthis Prospectus. SWS also may impose account charges, such asasset allocation fees, account maintenance fees, and othercharges that will reduce the net return on an investment in aPortfolio. If a SWS client has agreed to maintain a minimumbalance and the balance falls below this minimum, the clientmay be required to redeem all or a portion of the client’sinvestment in a Portfolio.

PORTFOLIO HOLDINGS. The Portfolios, or their duly authorizedservice providers, may publicly disclose holdings of allNorthern Institutional Funds in accordance with regulatoryrequirements, such as periodic portfolio disclosure in filingswith the SEC.

The Trust publishes on its website at northerntrust.com/institutional no later than the fifth business day of each monthand for a period of not less than six months, a completeschedule of a Portfolio’s holdings and certain other informationregarding portfolio holdings of each Portfolio as of the lastbusiness day of the prior month. A Portfolio may publish onthe Trust’s website a complete schedule of its portfolio holdingsand certain other information regarding portfolio holdingsmore frequently in accordance with the Trust’s policy. Certainportfolio information concerning the Portfolios will beprovided in monthly holdings reports to the SEC onForm N-MFP2. Form N-MFP2 will be made available to thepublic on the SEC’s EDGAR database immediately upon filingafter the end of the month to which the information pertains,and a link to each of the most recent 12 months of filings onForm N-MFP2 will be provided on the Trust’s website. Afurther description of the Trust’s Policy on Disclosure ofPortfolio Holdings is available in the SAI.

SHAREHOLDER COMMUNICATIONS. Shareholders of record willbe provided each year with a semiannual report showingportfolio investments and other information as of May 31 andwith an annual report containing audited financial statementsas of November 30. If we have received appropriate writtenconsent, we send a single copy of all materials, includingprospectuses, financial reports, proxy statements orinformation statements to all shareholders who share the samemailing address, even if more than one person in a householdholds shares of a Portfolio.

If you do not want your mailings combined with those of othermembers of your household, you may opt-out at any time bycontacting the Northern Institutional Funds Center bytelephone at 800-637-1380 or by mail at Northern InstitutionalFunds, P.O. Box 75986, Chicago, Illinois 60675-5986. You alsomay send an e-mail to [email protected]. ThePortfolios will begin sending individual copies to you within30 days after receipt of your opt-out notice. The Trust mayreproduce this Prospectus in electronic format that may beavailable on the Internet. If you have received this Prospectus inelectronic format you, or your representative, may contact theTransfer Agent for a free paper copy of this Prospectus bywriting to the Northern Institutional Funds Center at P.O.Box 75986, Chicago, Illinois 60675-5986, calling 800-637-1380or by sending an e-mail to: [email protected].



D I S T R I B U T I O N S A N D T A X C O N S I D E R A T I O N S

D I S T R I B U T I O N S

Dividends from net income are declared daily and paidmonthly by each Portfolio to its shareholders. Net incomeincludes the interest accrued on a Portfolio’s assets lessestimated expenses. Each Portfolio’s net realized short-termcapital gains, if any, are distributed at least annually. ThePortfolios do not expect to realize net long-term capital gains.

Dividends are paid as soon as practicable following the end ofeach month, except in the case of a total redemption of sharesin an account that is not subject to a standing order for thepurchase of additional shares of the same class. In that event,dividends will be paid promptly along with the redemptionproceeds.

All distributions are reinvested automatically (without any salescharge) in additional shares of the same Portfolio, unless youelect to receive distributions in cash by notifying the TransferAgent in writing. You may make arrangements to credit thesedistributions to your account with Northern Trust, its affiliatesor financial intermediaries.

There are no fees or sales charges on reinvestments.

T A X C O N S I D E R A T I O N S

The following is a summary of certain tax considerations thatmay be relevant to a shareholder in a Portfolio. The discussionsof the federal income tax consequences in this Prospectus andthe SAI are based on the Internal Revenue Code of 1986, asamended, and the regulations issued under it, and courtdecisions and administrative interpretations, as in effect on thedate of this Prospectus. Future legislative or administrativechanges or court decisions may significantly alter thestatements included herein, and any such changes or decisionsmay be retroactive. Except where otherwise indicated, thediscussion relates to shareholders who are individual U.S.citizens or residents and is based on current tax law. Youshould consult your tax professional for further informationregarding federal, state, local and/or foreign tax consequencesrelevant to your specific situation.

DISTRIBUTIONS. Each Portfolio intends to qualify as a regulatedinvestment company for federal income tax purposes and todistribute to shareholders substantially all of its net investmentincome each year. Except as otherwise noted below, you willgenerally be subject to federal income tax at ordinary rates on aPortfolio’s distributions to you, regardless of whether they arepaid in cash or reinvested in Portfolio shares. U.S. individualswith “modified adjusted gross income” exceeding $200,000($250,000 if married and filing jointly) and trusts and estateswith income above certain thresholds are subject to the

Medicare contribution tax on their “net investment income,”which includes non-exempt interest, dividends and capitalgains at a rate of 3.8%. You will be notified annually of the taxstatus of distributions to you.

The Portfolios generally will be invested in debt instrumentsand not in shares of stock on which dividend income will bereceived. As a result, the Portfolios do not expect to paydividends that are eligible for the reduced tax rate on corporatedividends or that will qualify for the dividends-receiveddeduction for corporations.

IRAS AND OTHER TAX-QUALIFIED PLANS. One major exceptionto the preceding tax principles is that distributions on sharesheld in an IRA (or other tax-qualified plan) will not becurrently taxable unless shares are acquired with borrowedfunds.

REDEMPTIONS—PRIME OBLIGATIONS PORTFOLIO. Because thePortfolio will not maintain a stable share price, but rather afloating NAV, a sale of Portfolio shares may result in a capitalgain or loss for you. Unless you choose to adopt a simplified“NAV method” of accounting (described below), with respectto your Portfolio shares, when you sell your shares, you willgenerally recognize a capital gain or loss in an amount equal tothe difference between your adjusted tax basis in the shares andthe amount received. Capital losses in any year are deductibleonly to the extent of capital gains, plus, in the case of anon-corporate taxpayer, generally $3,000 of income. Certainother special tax rules may apply to your capital gains or losseson Portfolio shares. Any liquidity fees you incur on sharesredeemed will generally decrease the amount of any capital gain(or increase the amount of any capital loss) you recognize withrespect to such redemption. This capital gain or loss is long-term or short-term depending on whether your holding periodexceeds one year.

If you elect to adopt the NAV method of accounting, ratherthan compute gain or loss on every taxable disposition ofPortfolio shares as described above, you would determine yourgain or loss based on the change in the aggregate value of yourPortfolio shares during a computation period (such as yourtaxable year), reduced by your net investment (cost of theshares purchased during the period, including shares acquiredthrough the reinvestment of dividends, minus amountsreceived during the period from dispositions of shares wheregain or loss would have been recognized if the NAV methodhad not been selected) in those shares during that period.Under the NAV method, any resulting net capital gain or losswould be treated as short-term capital gain or loss and will betreated as arising at the end of the computation period.

In addition, because of the so-called “wash sale” rules, any lossrealized by a shareholder on a redemption of Portfolio shareswould ordinarily be disallowed to the extent such shareholder



acquired new shares of the same Portfolio within 30 days beforeor after such a redemption. However, the Treasury Departmentand IRS have determined not to apply the wash sale rules to theredemption of investment company shares if the investmentcompany is regulated as, and holds itself out as, a moneymarket fund under Rule 2a-7 of the 1940 Act and has a floatingrate NAV at the time of redemption and the shareholder hasadopted the NAV method of accounting. Shareholders areurged to consult their tax professionals before deciding toadopt such accounting method.

REDEMPTIONS—U.S. GOVERNMENT SELECT PORTFOLIO.

Redemptions are treated as sales for tax purposes and generallyare taxable events for shareholders that are subject to tax. Ingeneral, if Portfolio shares are sold, a shareholder will recognizegain or loss equal to the difference between the amount realizedon the sale and the shareholder’s adjusted tax basis in theshares. As long as the Portfolio maintains a constant NAV of$1.00 per share, generally no gain or loss should be recognizedupon the sale of shares of the Portfolio.

BACKUP WITHHOLDING. The Trust will be required in certaincases to withhold and remit to the U.S. Treasury 24% of thedividends and gross sales proceeds paid to any shareholder(i) who had provided either an incorrect tax identificationnumber or no number at all, (ii) who is subject to backupwithholding by the Internal Revenue Service for failure toreport the receipt of taxable interest or dividend incomeproperly, or (iii) who has failed to certify to the Trust, whenrequired to do so, that he or she is not subject to backupwithholding or that he or she is an “exempt recipient.”

U.S. TAX TREATMENT OF FOREIGN SHAREHOLDERS. Portfoliodistributions attributable to Portfolio income such as interestwill generally be subject to a 30% withholding tax when paid toforeign shareholders. The withholding tax may, however bereduced (and in some cases eliminated) under an applicable taxtreaty between the United States and a shareholder’s country of

residence or incorporation, provided that the shareholderfurnishes the Portfolios with a properly completedForm W-8BEN or W-8BEN-E, as applicable, to establishentitlement for these treaty benefits. Dividends reported asshort-term capital gain dividends or interest-related dividendsare not subject to U.S. withholding tax. The exemption may notapply, however, if the recipient’s investment in a Portfolio isconnected to a trade or business of the recipient in the UnitedStates or if the recipient is present in the United States for 183days or more in a year and certain other conditions are met.However, dividends reported as exempt-interest dividends aregenerally not subject to U.S. withholding tax. In addition, thePortfolios are required to withhold 30% tax on certainpayments to certain foreign entities that do not meet specifiedinformation reporting requirements under the ForeignAccount Tax Compliance Act.

All foreign investors should consult their own tax professionalsregarding the tax consequences in their country of residence ofan investment in a Portfolio.

STATE AND LOCAL TAXES. You may also be subject to state andlocal taxes on income and gain attributable to your ownershipof Portfolio shares. State income taxes may not apply, however,to the portions of a Portfolio’s distributions, if any, that areattributable to interest earned by the Portfolio on U.S.government securities. You should consult your taxprofessional regarding the tax status of distributions in yourstate and locality.

CONSULT YOUR TAX PROFESSIONAL. Your investment in thePortfolios could have additional tax consequences. You shouldconsult your tax professional for information regarding all taxconsequences applicable to your investments in a Portfolio.More tax information relating to the Portfolios is also providedin the SAI. This short summary is not intended as a substitutefor careful tax planning.



S E C U R I T I E S , T E C H N I Q U E S A N D R I S K S

A D D I T I O N A L I N F O R M A T I O N O N I N V E S T M E N T

O B J E C T I V E S , P R I N C I P A L I N V E S T M E N T S T R A T E G I E S

A N D R E L A T E D R I S K S , D E S C R I P T I O N O F S E C U R I T I E S

A N D C O M M O N I N V E S T M E N T T E C H N I Q U E S

The following provides additional information regarding eachPortfolio’s investment objective, principal investment strategiesand related risks discussed in the Portfolio Summaries—Principal Investment Strategies section, as well as informationabout additional investment strategies and techniques that aPortfolio may employ in pursuing its investment objective.Principal investment strategies and risks for each Portfolio arenoted in parenthesis. The Portfolios also may make other typesof investments to the extent permitted by applicable law.Additional information about the Portfolios, their investmentstrategies and risks can also be found in the Portfolios’ SAI.

All investments carry some degree of risk that will affect thevalue of a Portfolio, its yield and investment performance andthe price of its shares. An investment in each of the Portfolios isnot a deposit of any bank and is not insured or guaranteed bythe FDIC, any other government agency or Northern Trust, itsaffiliates, subsidiaries or any other bank.

The Prime Obligations Portfolio is required to price andtransact in its shares at a floating NAV, rounded to the fourthdecimal place (e.g., $1.0000), and the U.S. Government SelectPortfolio seeks to maintain a stable NAV of $1.00 per share. It ispossible to lose money by investing in the Portfolios. Thissection takes a closer look at some of the Portfolios’ principalinvestment strategies and related risks.

The Portfolios:

▪ Limit their dollar-weighted average portfolio maturity to60 days or less;

▪ Limit their dollar-weighted average portfolio maturitywithout regard to maturity shortening provisions applicableto variable and floating rate securities (also known as dollar-weighted average portfolio life) to 120 days or less;

▪ Buy securities with remaining maturities of 397 days or less orsecurities otherwise permitted to be purchased because ofmaturity shortening provisions under Rule 2a-7; and

▪ Invest only in U.S. dollar-denominated securities thatrepresent minimal credit risks.

SEC regulations require each Portfolio to limit its dollar-weighted average portfolio maturity to 60 days or less, and itsdollar-weighted average portfolio life to 120 days or less. EachPortfolio also is required to comply with SEC requirementswith respect to the liquidity of the Portfolio’s investments.Specifically, each Portfolio is required to hold at least 10% of itstotal assets in “daily liquid assets,” and at least 30% of its total

assets in “weekly liquid assets.” For these purposes, daily andweekly liquid assets are calculated as of the end of each businessday. Daily liquid assets include: cash; direct obligations of theU.S. government; securities that will mature or are subject to ademand feature that is exercisable and payable within onebusiness day; and amounts receivable and due unconditionallywithin one business day on pending sales of portfolio securities.Weekly liquid assets include: cash; direct obligations of the U.S.government; certain U.S. government agency discount noteswithout provision for the payment of interest with remainingmaturities of 60 days or less; securities that will mature or aresubject to a demand feature that is exercisable and payablewithin five business days; and amounts receivable and dueunconditionally within five business days on pending sales ofportfolio securities.

In addition, each Portfolio limits its investments to “Eligiblesecurities” as defined by the SEC. Securities in which thePortfolios may invest may not earn as high a level of income aslong-term or lower quality securities, which generally havegreater market risk and more fluctuation in market value.

Rule 2a-7 requires money market funds to purchase securitiesthat have a remaining maturity of no more than 397 calendardays (unless otherwise permitted under Rule 2a-7), and(i) which have been determined by a money market fund’sboard of trustees (or the fund’s investment adviser, if the boardof trustees delegates such power to the adviser) to presentminimal credit risks to the fund; (ii) are issued by otherinvestment companies that are money market funds; or (iii) areU.S. government securities. NTI considers several factorsincluding the capacity of each security’s issuer or guarantor tomeet its financial obligations.

In accordance with current SEC regulations, each Portfoliogenerally will not invest more than: (1) 5% of the value of itstotal assets at the time of purchase in the securities of any singleissuer (and certain affiliates of that issuer); and (2) 10% of thevalue of its total assets at the time of purchase in the securitiessubject to demand features or guarantees of any singleinstitution. The Portfolios may, however, invest up to 25% oftheir total assets in the securities of a single issuer for up tothree Business Days. These limitations do not apply to cash,certain repurchase agreements, U.S. government securities orsecurities of other investment companies that are moneymarket funds. In addition, securities subject to demand featuresand guarantees are subject to different diversificationrequirements as described in the SAI.

FLOATING NAV RISK (principal risk for the Prime ObligationsPortfolio) is the risk that because the share price of the PrimeObligations Portfolio will fluctuate, when you sell your shares theymay be worth more or less than what you originally paid for them.A sale of Portfolio shares may result in capital gains or losses.



STABLE NAV RISK (principal risk for the U.S. Government SelectPortfolio) is the risk that the U.S. Government Select Portfoliowill not be able to maintain a NAV per share of $1.00 at alltimes. If the Portfolio fails to maintain a stable NAV (or if thereis a perceived threat of such a failure), the Portfolio could besubject to increased redemption activity, which could adverselyaffect its NAV. A significant enough market disruption or dropin market prices of securities held by a Portfolio, especially at atime when the Portfolio needs to sell securities to meetshareholder redemption requests, could cause the value of thePortfolio’s shares to decrease to a price less than $1.00 pershare.

LIQUIDITY FEE AND REDEMPTION GATE RISK (principal risk forthe Prime Obligations Portfolio) is the risk that the PrimeObligations Portfolio may impose a “liquidity fee” (up to 2%)or “redemption gate” that temporarily restricts your ability tosell shares for up to 10 business days if the Portfolio’s liquidityfalls below required minimums because of market conditionsor other factors. An investment in the Portfolio is not a depositof a bank and is not insured or guaranteed by the FederalDeposit Insurance Corporation or The Northern TrustCompany, its affiliates, subsidiaries or any other bank. ThePortfolio’s sponsor has no legal obligation to provide financialsupport to the Portfolio, and you should not expect that thesponsor will provide financial support to the Portfolio at anytime.

INVESTMENT OBJECTIVES. The investment objective of thePrime Obligations Portfolio may be changed by the Trust’sBoard of Trustees without shareholder approval. Shareholderswill, however, be notified of any changes. Any such change mayresult in the Prime Obligations Portfolio having an investmentobjective different from the objective that the shareholderconsidered appropriate at the time of investment in the PrimeObligations Portfolio.

During extraordinary market conditions and interest rateenvironments, all or any portion of the Portfolios’ assets maybe uninvested and will therefore not generate income. ThePortfolios may not achieve their investment objectives duringthis time.

The investment objective of the U.S. Government SelectPortfolio may not be changed without shareholder approval.

Under unusual circumstances, the U.S. Government SelectPortfolio may invest less than 50% of its net assets in U.S.government securities that pay interest exempt from stateincome taxation. The Portfolio may also invest in repurchaseagreements that are fully collateralized by cash or U.S.government securities and hold uninvested cash.

ASSET-BACKED SECURITIES (principal strategy for the PrimeObligations Portfolio). Asset-backed securities are sponsored byentities such as government agencies, banks, financialcompanies and commercial or industrial companies. Asset-backed securities represent participations in, or are secured byand payable from, pools of assets such as mortgages, motorvehicle installment sale contracts, installment loan contracts,leases of various types of real and personal property, receivablesfrom revolving credit (credit card) agreements, municipalsecurities and other financial assets.

Such asset pools are securitized through the use of privately-formed trusts or special purpose corporations. Payments ordistributions of principal and interest may be guaranteed up tocertain amounts and for a certain time period by a letter ofcredit or a pooled insurance policy issued by a financialinstitution, or by other credit enhancements.

INVESTMENT STRATEGY. The Prime Obligations Portfolio maypurchase various types of asset-backed securities that are“Eligible Securities” as defined by the SEC. The U.S.Government Select Portfolio may purchase asset-backedsecurities (such as mortgage-backed securities) that are issuedor guaranteed by the U.S. government or by its agencies,instrumentalities or sponsored enterprises.

SPECIAL RISKS. In addition to credit and market risk, asset-backed securities may involve prepayment risk because theunderlying assets (loans) may be prepaid at any time.Prepayment (or call) risk is the risk that an issuer will exerciseits right to pay principal on an obligation held by a Portfolio(such as an asset-backed security) sooner than expected. Thismay happen during a period of falling interest rates.Accordingly, a Portfolio’s ability to maintain positions in suchsecurities will be affected by reductions in the principal amountof such securities resulting from prepayments, and its ability toreinvest the returns of principal at comparable yields is subjectto generally prevailing interest rates at that time.

The value of these securities also may change because of actualor perceived changes in the creditworthiness of the originator,the service agent, the financial institution providing the creditsupport, or the counterparty. Unlike mortgage-backedsecurities issued or guaranteed by agencies of the U.S.government or government-sponsored enterprises, mortgage-backed securities issued by private issuers do not have agovernment or government-sponsored enterprise guarantee(but may have other credit enhancement), and may, andfrequently do, have less favorable collateral, credit risk or otherunderwriting characteristics. Credit supports generally applyonly to a fraction of a security’s value. Like other fixed-incomesecurities, when interest rates rise, the value of an asset-backed



security generally will decline. However, when interest ratesdecline, the value of an asset-backed security with prepaymentfeatures may not increase as much as that of other fixed-incomesecurities. In addition, non-mortgage asset-backed securitiesinvolve certain risks not presented by mortgage-backedsecurities. Primarily, these securities do not have the benefit ofthe same security interest in the underlying collateral. Creditcard receivables generally are unsecured, and the debtors areentitled to the protection of a number of state and federalconsumer credit laws.

Automobile receivables are subject to the risk that the trusteefor the holders of the automobile receivables may not have aneffective security interest in all of the obligations backing thereceivables. If the issuer of the security has no security interestin the related collateral, there is the risk that a Portfolio couldlose money if the issuer defaults. The economic recession thatcommenced in the United States in 2008, introduced a periodof heightened levels of default on the receivables and loansunderlying asset-backed securities than were historicallyexperienced. A future economic downturn could increase therisk that such assets underlying asset-backed securitiespurchased by the Portfolios will also suffer greater levels ofdefault than were historically experienced. In addition toprepayment risk, investments in mortgage-backed securitiescomprised of subprime mortgages and investments in otherasset-backed securities of underperforming assets may besubject to a higher degree of credit risk, valuation risk andliquidity risk.

BORROWINGS AND REVERSE REPURCHASE AGREEMENTS. ThePortfolios may borrow money from banks and may enter intoreverse repurchase agreements with banks and other financialinstitutions.

INVESTMENT STRATEGY. Each Portfolio may borrow moneyfrom banks and enter into reverse repurchase agreements withbanks and other financial institutions in amounts notexceeding one-fourth of the value of its total assets (includingthe amount borrowed). The Portfolios may enter into reverserepurchase agreements when the Investment Adviser expectsthat the interest income to be earned from the investment ofthe transaction proceeds will be greater than the related interestexpense.

SPECIAL RISKS. Borrowings and reverse repurchase agreementsinvolve leveraging. Reverse repurchase agreements involve thesale of money market securities held by a Portfolio subject tothe Portfolio’s agreement to repurchase them at a mutuallyagreed upon date and price (including interest). If the securitiesheld by the Portfolios decline in value while these transactionsare outstanding, the NAV of the Portfolios’ outstanding shareswill decline in value by proportionately more than the declinein value of the securities. In addition, reverse repurchase

agreements involve the risks that (a) the interest income earnedby a Portfolio (from the investment of the proceeds) will be lessthan the interest expense of the transaction; (b) the marketvalue of the securities sold by a Portfolio will decline below theprice the Portfolio is obligated to pay to repurchase thesecurities; and (c) the securities may not be returned to thePortfolio.

COMMERCIAL PAPER RISK (principal risk for Prime ObligationsPortfolio). Commercial paper is a short-term obligation with amaturity generally ranging from one to 270 days and is issuedby U.S. or foreign companies or other entities in order tofinance their current operations. Such investments are generallyunsecured and usually discounted from their value at maturity.The value of commercial paper may be affected by changes inthe credit rating or financial condition of the issuing entitiesand will tend to fall when interest rates rise and rise wheninterest rates fall. Asset-backed commercial paper may beissued by structured investment vehicles or other conduits thatare organized to issue the commercial paper and to purchasetrade receivables or other financial assets. The repayment ofasset-backed commercial paper depends primarily on the cashcollections received from such an issuer’s underlying assetportfolio and the issuer’s ability to issue new asset-backedcommercial paper (See also “Asset-Backed Securities” above).

Investments in commercial paper are subject to the risk that theissuer cannot issue enough new commercial paper to satisfy itsobligations with respect to its outstanding commercial paper,also known as rollover risk. Commercial paper is alsosusceptible to changes in the issuer’s financial condition orcredit quality. In addition, under certain circumstancescommercial paper may become illiquid or may suffer fromreduced liquidity. Commercial paper is generally unsecured,which increases the credit risk associated with this type ofinvestment.

CREDIT FACILITY AND BORROWING. The portfolios of theTrust, including the Portfolios, and affiliated funds of NorthernFunds (each a “Fund”, and together the “Funds”) have jointlyentered into a revolving credit facility (the “Credit Facility”)whereby the Portfolios, the other portfolios in the Trust, andthe Funds may borrow for the temporary funding ofshareholder redemptions or for other temporary or emergencypurposes. Pursuant to the Credit Facility, the participatingportfolios and Funds may borrow up to an aggregatecommitment amount of $250 million (the “CommitmentLimit”) at any time, subject to asset coverage and otherlimitations as specified in the Credit Facility and under the1940 Act. The Portfolios may borrow up to the maximumamount allowable under their current prospectuses and SAIs,subject to various other legal, regulatory or contractual limits,including the asset coverage limits in the Credit Facility.



Borrowing results in interest expense and other fees andexpenses for the Portfolios that may impact the Portfolios’expenses, including any net expense ratios. The costs ofborrowing may reduce the Portfolios’ yield. If a Portfolioborrows pursuant to the Credit Facility, it is charged interest ata variable rate. Each Portfolio also pays a commitment fee equalto its pro rata share of the unused portion of the Credit Facility.The availability of funds under the Credit Facility can beaffected by other participating Portfolio’s or Funds’ borrowingsunder the Credit Facility. As such, a Portfolio may be unable toborrow (or borrow further) under the Credit Facility if theCommitment Limit has been reached.

CREDIT (OR DEFAULT) RISK (principal risk for each Portfolio) isthe risk that an issuer of fixed-income securities held by aPortfolio may default on its obligation to pay interest and repayprincipal. Generally, the lower the credit rating of a security,the greater the risk that the issuer of the security will default onits obligation. High quality securities are generally believed tohave relatively low degrees of credit risk. The Portfolios intendto enter into financial transactions with counterparties that arecreditworthy at the time of the transactions. There is always therisk that the Investment Adviser’s analysis of creditworthiness isincorrect or may change due to market conditions. Concernsover an issuer’s ability to make principal or interest paymentsmay cause the value of a fixed income security to decline. Tothe extent that a Portfolio focuses its transactions with a limitednumber of counterparties, it will be more susceptible to therisks associated with one or more counterparties.

CUSTODIAL RECEIPTS FOR TREASURY SECURITIES. Custodialreceipts are participations in trusts that hold U.S. Treasurysecurities and are sold under such names as TIGRs (TreasuryIncome Growth Receipts) and CATS (Certificates of Accrual onTreasury Securities). Like other stripped obligations, theyentitle the holder to future interest payments or principalpayments on the U.S. Treasury securities.

INVESTMENT STRATEGY. To the extent consistent with itsinvestment objectives and strategies, the Prime ObligationsPortfolio may invest a portion of its assets in custodial receipts.

SPECIAL RISKS. Like other stripped securities (which aredescribed below), stripped custodial receipts may be subject togreater price volatility than ordinary debt obligations becauseof the way in which their principal and interest are returned toinvestors. Custodial receipts may not be considered obligationsof the U.S. government or other issuer of the security held bythe custodian for the purposes of securities laws. If for taxpurposes, a Portfolio is not considered to be the owner of thesecurities held in the underlying trust or custodial account, thePortfolio may suffer adverse tax consequences. As a holder ofcustodial receipts, a Portfolio will bear its proportionate shareof the fees or expenses charged to the custodial account.

CYBERSECURITY RISK (principal risk for each Portfolio). With theincreased use of the Internet and because informationtechnology (“IT”) systems and digital data underlie most of thePortfolios’ operations, the Portfolios and their investmentadviser, custodian, transfer agent, distributor and other serviceproviders and the financial intermediaries of each (collectively“Service Providers”) are exposed to the risk that theiroperations and data may be compromised as a result of internaland external cyber-failures, breaches or attacks (“Cyber Risk”).This could occur as a result of malicious or criminal cyber-attacks. Cyber-attacks include actions taken to: (i) steal orcorrupt data maintained online or digitally, (ii) gainunauthorized access to or release confidential information,(iii) shut down a Portfolio or Service Provider website throughdenial-of-service attacks, or (iv) otherwise disrupt normalbusiness operations. However, events arising from humanerror, faulty or inadequately implemented policies andprocedures or other systems failures unrelated to any externalcyber-threat may have effects similar to those caused bydeliberate cyber-attacks.

Successful cyber-attacks or other cyber-failures or eventsaffecting the Portfolios or their Service Providers may adverselyimpact a Portfolio or its shareholders. For instance, suchattacks, failures or other events may interfere with theprocessing of shareholder transactions, impact a Portfolio’sability to calculate its NAV, cause the release of privateshareholder information or confidential Portfolio information,impede trading, or cause reputational damage. Such attacks,failures or other events could also subject the Portfolios or theirService Providers to regulatory fines, penalties or financiallosses, reimbursement or other compensation costs, and/oradditional compliance costs. Insurance protection andcontractual indemnification provisions may be insufficient tocover these losses. The Portfolios or their Service Providers mayalso incur significant costs to manage and control Cyber Risk.While the Portfolios and their Service Providers haveestablished IT and data security programs and have in placebusiness continuity plans and other systems designed toprevent losses and mitigate Cyber Risk, there are inherentlimitations in such plans and systems, including the possibilitythat certain risks have not been identified or that cyber-attacksmay be highly sophisticated.

Cyber Risks are also present for issuers of securities or otherinstruments in which the Portfolios invest, which could resultin material adverse consequences for such issuers, and maycause the Portfolios’ investment in such issuers to lose value.

DERIVATIVES. Each Portfolio may purchase certain “derivative”instruments. A derivative is a financial instrument whose valueis derived from, or based upon, the performance of underlyingassets, interest rates, or other indices. Derivatives include



structured securities such as collateralized mortgage obligationsand other types of asset-backed securities, “stripped” securitiesand various floating rate instruments.

INVESTMENT STRATEGY. A Portfolio may invest in derivativeswhen the Investment Adviser believes the potential risks andrewards are consistent with the Portfolio’s objective, strategiesand overall risk profile.

SPECIAL RISKS. Engaging in derivative transactions involvesspecial risks, including (a) market risk that the Portfolio’sderivatives position will lose value; (b) credit risk that thecounterparty to the transaction will default; (c) leveraging riskthat the value of the derivative instrument will decline morethan the value of the assets on which it is based; (d) riskspertaining to illiquid investments that a Portfolio will be unableto sell its position because of lack of market depth ordisruption; (e) pricing risk that the value of a derivativeinstrument will be difficult to determine; and (f) operationsrisk that loss will occur as a result of inadequate systems orhuman error. Many types of derivatives have been developedrecently and have not been tested over complete market cycles.For these reasons, a Portfolio may suffer a loss whether or notthe analysis of the Investment Adviser is accurate.

FINANCIAL SERVICES INDUSTRY RISK (principal risk for PrimeObligations Portfolio). The financial services industry includesthe group of industries within the financial services sector.Asset-backed securities with underlying assets related to thefinancial services industry are grouped by the InvestmentAdviser within the financial services industry. Companies in thefinancial services group of industries include, but are notlimited to, U.S. and non-U.S. companies involved in banking,mortgage, consumer or specialized finance, investmentbanking, securities brokerage, asset management and custody,insurance, financial investment, real estate and mortgagefinance and financial conglomerates, and related asset-backedsecurities.

INVESTMENT STRATEGY. The Prime Obligations Portfolio willconcentrate its investments in the financial services industry.Therefore, under normal market conditions, the PrimeObligations Portfolio will invest at least 25% of its total assets insecurities issued by companies in the financial services industry.The Prime Obligations Portfolio may, however, for temporarydefensive purposes, invest less than 25% of its total assets in thefinancial services industry if warranted due to adverseeconomic conditions or if investing less than 25% of its totalassets in the financial services industry appears to be in the bestinterest of shareholders.

SPECIAL RISKS. Because the Prime Obligations Portfolio willunder normal market conditions invest at least 25% of its totalassets in the financial services industry, the Portfolio will be

subject to greater risk of loss by economic, business, political orother developments which generally affect this industry.Changes in government regulation, interest rates and economicdownturns can have a significant negative effect on issuers inthe financial services sector, including the price of theirsecurities or their ability to meet their payment obligations. Theprofitability of financial services companies is dependent on theavailability and cost of capital and can be significantly affectedby changes in interest rates and monetary policy. Financialservices companies are also exposed to losses if borrowers andother counterparties experience financial problems and/orcannot repay their obligations. Financial services companiesalso are subject to extensive government regulation, includingpolicy and legislative changes in the United States and othercountries that are changing many aspects of financialregulation. In June 2016, the United Kingdom (“UK”) held areferendum election and voters elected to withdraw from theEuropean Union (“EU”). The withdrawal, colloquially knownas “Brexit,” was agreed to and ratified by the UK Parliament,and the UK left the EU on January 31, 2020. A transitionperiod, currently set to last through December 31, 2020, will beused for the UK and EU to negotiate their future relationship.Financial services companies that operate in the UnitedKingdom or European Union could be disproportionatelyimpacted by volatile trading markets and significant andunpredictable currency fluctuations caused by these actions.(See also, “Market Events Risk” below).

When interest rates go up, the value of securities issued bymany types of financial services companies generally goesdown. In many countries, financial services and the companiesthat provide them are regulated by governmental entities,which can increase costs for new services or products and makeit difficult to pass increased costs on to consumers. In certainareas, deregulation of financial services companies has resultedin increased competition and reduced profitability for certaincompanies.

The profitability of many types of financial services companiesmay be adversely affected in certain market cycles, includingperiods of rising interest rates, which may restrict theavailability and increase the cost of capital, and decliningeconomic conditions, which may cause credit losses due tofinancial difficulties of borrowers. Because many types offinancial services companies are vulnerable to these economiccycles, a large portion of the Portfolio’s investments may losevalue during such periods.

FOREIGN INVESTMENTS (principal strategy for the PrimeObligations Portfolio). To the extent consistent with itsinvestment objective and strategies, the Prime ObligationsPortfolio may invest in U.S. dollar-denominated obligationsissued or guaranteed by one or more foreign governments or



any of their political subdivisions, agencies or instrumentalities,foreign commercial banks and foreign branches of U.S. banks.The Prime Obligations Portfolio also may invest in U.S. dollar-denominated commercial paper and other obligations offoreign issuers. Foreign government obligations may includedebt obligations of supranational entities, includinginternational organizations (such as The International Bank forReconstruction and Development (also known as the WorldBank)) and international banking institutions and relatedgovernment agencies.

SPECIAL RISKS. Foreign securities involve special risks and costs,which are considered by the Investment Adviser in evaluatingthe creditworthiness of issuers and making investmentdecisions for the Portfolio. Foreign securities fluctuate in pricebecause of political, financial, social and economic events inforeign countries (including, for example, militaryconfrontations, war and terrorism). A foreign security couldalso lose value because of more or less stringent foreignsecurities regulations and less stringent accounting anddisclosure standards. In addition, foreign markets may havegreater volatility than domestic markets and foreign securitiesmay be less liquid and harder to value than domestic securities.Certain foreign markets may rely heavily on particularindustries or foreign capital and are more vulnerable todiplomatic developments, the imposition of economicsanctions against a particular country or countries,organizations, entities and/or individuals, changes ininternational trading patterns, trade barriers, and otherprotectionist or retaliatory measures. International tradebarriers or economic sanctions against foreign countries,organizations, entities and/or individuals may adversely affect aPortfolio’s foreign holdings or exposures. Foreign securities,and in particular foreign debt securities, are sensitive to changesin interest rates. In addition, investment in the securities offoreign governments involves the risk that foreign governmentsmay default on their obligations or may otherwise not respectthe integrity of their debt.

Investment in foreign securities may involve higher costs thaninvestment in U.S. securities, including higher transaction andcustody costs as well as the imposition of additional taxes byforeign governments. Foreign investments also may involverisks associated with the level of currency exchange rates, lesscomplete financial information about the issuers, less marketliquidity, more market volatility and political instability.Moreover, clearance and settlement procedures may differ fromthose in the U.S. and in certain markets such procedures havebeen unable to keep pace with the volume of securitiestransactions, thus making it difficult to conduct suchtransactions. Future political and economic developments, thepossible imposition of withholding taxes on dividend income,the possible seizure or nationalization of foreign holdings, the

possible establishment of exchange controls or freezes on theconvertibility of currency, trade restrictions (including tariffs)or the adoption of other governmental restrictions mightadversely affect an investment in foreign securities.Additionally, foreign banks and foreign branches of domesticbanks may be subject to less stringent reserve requirements andto different accounting, auditing and recordkeepingrequirements. The Investment Adviser may determine not toinvest in, or may limit the Portfolio’s overall investment in, aparticular issuer, country or geographic region due to, amongother things, heightened risks regarding repatriationrestrictions, confiscation of assets and property, expropriationor nationalization.

GUARANTOR (OR CREDIT ENHANCEMENT) RISK (principal riskfor the Prime Obligations Portfolio) is the risk that changes incredit quality of a U.S. or foreign bank, insurance company orother financial institution or such entity’s failure to fulfill itsobligations could cause a Portfolio’s investments in securitiesbacked by guarantees, letters of credit, insurance or other creditenhancements issued by such bank or institution to decline invalue. Guarantees, letters of credit, insurance or other creditenhancements do not protect a Portfolio or its shareholdersfrom losses caused by declines in a security’s market value. Inaddition, having multiple securities’ credit enhanced by thesame enhancement provider will increase the adverse effects ona Portfolio that are likely to result from a downgrading of, or adefault by, such enhancement provider. Adverse developmentsin the banking or bond insurance industries also may negativelyaffect a Portfolio.

ILLIQUID OR RESTRICTED INVESTMENTS. An illiquid investmentis an investment that a Portfolio reasonably expects cannot besold or disposed of in the ordinary course of business within 7calendar days at approximately the value ascribed to it by thePortfolio. Illiquid securities include repurchase agreements andtime deposits with notice/termination dates of more than sevendays, certain variable amount master demand notes that cannotbe called within seven days, certain insurance fundingagreements (see “Insurance Funding Agreements” on page 32),derivative instruments, and securities and other financialinstruments that are not readily marketable, and 144ASecurities (as defined below), and both foreign and domesticsecurities that are not readily marketable, unless, based upon areview of the relevant market, trading and investment-specificconsiderations, those investments are determined not to beilliquid.

INVESTMENT STRATEGY. A Portfolio may invest up to 5% of itstotal assets in illiquid investments. A domestically tradedsecurity that is not registered under the Securities Act of 1933,as amended (the “1933 Act”) will not be considered illiquid ifthe Investment Adviser determines that an adequate trading



market exists for that security. If otherwise consistent with theirinvestment objectives and strategies, the Portfolios maypurchase commercial paper issued pursuant to Section 4(a)(2)of the 1933 Act and securities that are not registered under the1933 Act but can be sold to “qualified institutional buyers” inaccordance with Rule 144A under the 1933 Act (“Rule 144ASecurities”). These securities will not be considered illiquid solong as the Investment Adviser determines, that underguidelines approved by the Trust’s Board of Trustees, anadequate trading market exists.

SPECIAL RISKS. Because illiquid and restricted investments maybe difficult to sell at an acceptable price, they may be subject togreater volatility and may result in a loss to a Portfolio. Thepractice of investing in Rule 144A Securities and commercialpaper available to qualified institutional buyers could increasethe level of a Portfolio’s illiquidity during any period thatqualified institutional buyers become uninterested inpurchasing these securities. Investments purchased by aPortfolio that are liquid at the time of purchase maysubsequently become illiquid due to events relating to theissuer, market events, economic conditions and/or investorperception. To the extent an investment held by a Portfolio isdeemed to be an illiquid investment or a less liquid investment,a Portfolio will be exposed to greater liquidity risk.

INCOME RISK (principal risk for each Portfolio) is the risk thatfalling interest rates will cause the Portfolio’s income to decline.Income risk is generally higher for short-term debt securities.

INSURANCE FUNDING AGREEMENTS. An insurance fundingagreement (“IFA”) is an agreement that requires a Portfolio tomake cash contributions to a deposit fund of an insurancecompany’s general account. The insurance company thencredits interest to the Portfolio for a set time period.

INVESTMENT STRATEGY. The Prime Obligations Portfolio mayinvest in IFAs issued by insurance companies that meet qualityand credit standards established by the Investment Adviser.

SPECIAL RISKS. IFAs are not insured by a government agency—they are backed only by the insurance company that issuesthem. As a result, they are subject to default risk of thenon-governmental issuer. In addition, the transfer of IFAs maybe restricted and an active secondary market in IFAs currentlydoes not exist. This means that it may be difficult or impossibleto sell an IFA at an appropriate price or that these investmentsmay be considered illiquid.

INTEREST RATE RISK (principal risk for all Portfolios). APortfolio’s yield will vary with changes in interest rates. Recentand any future declines in interest rate levels could cause aPortfolio’s earnings to fall below the Portfolio’s expense ratio,resulting in a negative yield and a decline in the Portfolio’sshare price. During periods of rising interest rates, a Portfolio’s

yield (and the market value of its securities) will tend to belower than prevailing market rates; in periods of falling interestrates, a Portfolio’s yield (and the market value of its securities)will tend to be higher. In a period of rising interest rates, aPortfolio’s yield may not rise as quickly as the yields of certainother short-term investments. Investments held by a Portfoliowith longer maturities will tend to be more sensitive to interestrate changes than investments with shorter maturities. Ifinterest rates rise, the Portfolios’ yields may not increaseproportionately. Changing interest rates may haveunpredictable effects on the markets and the Portfolios’investments. A low interest rate environment may prevent aPortfolio from providing a positive yield or paying Portfolioexpenses out of Portfolio assets and could lead to a decline in aPortfolio’s share price. Additionally, securities issued orguaranteed by the U.S. government, its agencies,instrumentalities and sponsored enterprises have historicallyinvolved little risk of loss of principal if held to maturity.However, due to fluctuations in interest rates, the market valueof such securities held by a Portfolio may vary.

INTERFUND BORROWING AND LENDING. The SEC has grantedan exemption permitting the Portfolios to participate in aninterfund borrowing and lending program. This interfundborrowing and lending program allows the Portfolios toborrow money from other portfolios in the Trust and otheraffiliated funds of Northern Funds (each a “Fund” and togetherthe “Funds”) advised by NTI, and to lend money to otherportfolios in the Trust, for temporary or emergency purposes.The interfund borrowing and lending program is currently notoperational. The interfund borrowing and lending program issubject to a number of conditions, including, among otherthings, the requirements that (1) a Portfolio may not borrow orlend money through the program unless it receives a morefavorable interest rate than is available from a bank loan rate orinvestment yield rate, respectively; (2) loans will be secured onan equal priority basis with at least an equivalent percentage ofcollateral to loan value as any outstanding bank loan thatrequires collateral; (3) loans will have a maturity no longer thanthat of any outstanding bank loan (and in any event not overseven days); (4) if an event of default occurs under anyagreement evidencing an outstanding bank loan to a Portfolio,the event of default will automatically (without need for actionor notice by the lending Portfolio or Fund) constitute animmediate event of default under the Interfund LendingAgreement entitling the lending Portfolio or Fund to call theinterfund loan (and exercise all rights with respect to anycollateral) and that such call will be made if the bank exercisesits right to call its loan under its agreement with a Portfolio;(5) a Portfolio may not borrow money if the loan would causeits outstanding borrowings from all sources to exceed 10% ofits net assets at the time of the loan, except that a Portfolio may



borrow up to 33 1/3% of its total assets through the program orfrom other sources if each interfund loan is secured by thepledge of segregated collateral with a market value of at least102% of the outstanding principal value of the loan; (6) aPortfolio may not loan money if the loan would cause itsaggregate outstanding loans through the program to exceed15% of its net assets at the time of the loan; (7) a Portfolio’sinterfund loans to any one Portfolio shall not exceed 5% of thelending Portfolio’s net assets; and (8) a Portfolio’s borrowingsthrough the program will not exceed the greater of 125% of thePortfolio’s total net cash redemptions or 102% of thePortfolio’s sales fails (when a sale of securities “fails,” due tocircumstances beyond the Portfolio’s control) for the precedingseven calendar days as measured at the time of the loan. Inaddition, a Portfolio may participate in the interfundborrowing and lending program only if and to the extent thatsuch participation is consistent with the Portfolio’s investmentobjective and policies. The Board of Trustees of the Trust isresponsible for overseeing the interfund borrowing and lendingprogram. A delay in repayment to a lending Portfolio couldresult in a lost investment opportunity or additional lendingcosts.

INVESTMENT COMPANIES. To the extent consistent with itsinvestment objective and strategies, each Portfolio may investin securities issued by other affiliated or unaffiliated investmentcompanies.

INVESTMENT STRATEGY. Investments by a Portfolio in otherinvestment companies will be subject to the limitations of the1940 Act and SEC orders. Although the Portfolios do not expectto do so in the foreseeable future, each Portfolio is authorizedto invest substantially all of its assets in an open-end investmentcompany or a series thereof that has substantially the sameinvestment objective, strategies and fundamental restrictions asthe Portfolio.

SPECIAL RISKS. As a shareholder of another investmentcompany, a Portfolio would be subject to the same risks as anyother investor in that company. It would also bear aproportionate share of any fees or expenses paid by thatcompany. These expenses would be in addition to themanagement fees and other expenses the Portfolio bearsdirectly in connection with its own operations.

LARGE SHAREHOLDER RISK (principal risk for each Portfolio). Tothe extent a significant percentage of the shares of a Portfolioare owned or controlled by a small number of accountshareholders (or a single account shareholder), including fundsor accounts over which the Investment Adviser or an affiliate ofthe Investment Adviser has investment discretion, the Portfoliois subject to the risk that those shareholders may purchase orredeem Portfolio shares in significant amounts rapidly orunexpectedly, including as a result of an asset allocation

decision made by the Investment Adviser or an affiliate of theInvestment Adviser and may adversely affect a Portfolio’sperformance if the Investment Adviser is forced to sell portfoliosecurities or invest cash when the Investment Adviser wouldnot otherwise choose to do so. Redemptions of a large numberof shares may affect the liquidity of a Portfolio, increase thePortfolio’s transaction costs, and accelerate the realization oftaxable income and/or gains. For the Prime ObligationsPortfolio, a large shareholder redemption may result in thePortfolio imposing a liquidity fee or redemption gate thattemporarily restricts your ability to sell shares for up to 10business days if the Portfolio’s liquidity falls below requiredminimums. Such sales may also accelerate the increase oftaxable income to shareholders if these sales result in gains, andmay also increase transaction costs. In addition, a largeredemption could result in each Portfolio’s current expensesbeing allocated over a smaller asset base, leading to an increasein each such Portfolio’s expense ratio. Similarly, large sharepurchases may adversely affect the Portfolios’ performance tothe extent that the Portfolios are delayed in investing new cashor otherwise maintain a larger cash position than theyordinarily would.

LIBOR TRANSITION Certain of a Portfolio’s investments,payment obligations and financing terms may be based onfloating rates, such as London Interbank Offered Rate(“LIBOR”), Euro Interbank Offered Rate and other similartypes of reference rates (each, a “Reference Rate”). On July 27,2017, the Chief Executive of the UK Financial ConductAuthority (“FCA”), which regulates LIBOR, announced thatthe FCA will no longer persuade nor compel banks to submitrates for the calculation of LIBOR and certain other ReferenceRates after 2021. Such announcement indicates that thecontinuation of LIBOR and other Reference Rates on thecurrent basis cannot and will not be guaranteed after 2021. Thetransition away from Reference Rates may lead to increasedvolatility and illiquidity in markets that are tied to suchReference Rates and reduced values of Reference Rate-relatedinvestments. This announcement and any additional regulatoryor market changes that occur as a result of the transition awayfrom Reference Rates may have an adverse impact on aPortfolio’s investments, performance or financial condition.

LIQUIDITY RISK (principal risk for the Prime Obligations Portfolio)is the risk that a Portfolio will not be able to pay redemptionproceeds within the time periods described in this Prospectusbecause of unusual market conditions, an unusually highvolume of redemption requests, legal restrictions impairing itsability to sell particular securities at an advantageous marketprice or other reasons. Certain portfolio securities may be lessliquid than others, which may make them difficult or impossibleto sell at the time and the price that a Portfolio would like ordifficult to value. A Portfolio may have to lower the price, sell



other securities instead or forgo an investment opportunity. Inaddition, certain assets that a Portfolio wants to buy may bedifficult or impossible to purchase. Any of these events couldhave a negative effect on portfolio management or performance.For the Prime Obligations Portfolio, these factors may result inthe Portfolio imposing a liquidity fee or redemption gate thattemporarily restricts your ability to sell shares for up to 10business days if the Portfolio’s liquidity falls below requiredminimums. Liquidity risk may be the result of, among otherthings, the reduced number and capacity of traditional marketparticipants to make a market in fixed income securities. As ageneral matter, dealers recently have been less willing to makemarkets for fixed income securities. The potential for liquidityrisk may be magnified by a rising interest rate environment orother circumstances where investor redemptions from moneymarket and other fixed income mutual funds may be higherthan normal, potentially causing increased supply in the marketdue to selling activity. Portfolios with principal investmentstrategies that involve investments in securities of companieswith smaller market capitalizations, foreign securities,derivatives or securities with potential market and/or credit risktend to have the greatest exposure to liquidity risk. All of theserisks may increase during periods of market volatility. Theliquidity of certain assets, such as privately issued andnon-investment grade mortgage- and asset-backed securities,may be difficult to ascertain and may change over time.Transactions in less liquid securities may entail transaction coststhat are higher than those for transactions in more liquidsecurities.

MARKET EVENTS RISK relates to the increased volatility,depressed valuations, decreased liquidity and heighteneduncertainty in the financial markets throughout the worldduring the past decade. These conditions may recur.

The U.S. government and the Federal Reserve, as well as certainforeign governments and central banks, have taken steps tosupport financial markets, including by keeping interest rates athistorically low levels. This and other government interventionmay not work as intended, particularly if the efforts areperceived by investors as being unlikely to achieve the desiredresults. In recent years, the U.S. government and FederalReserve have reduced their market support activities and havebegun raising interest rates. Certain foreign governments andcentral banks have implemented so-called negative interestrates (e.g., charging depositors who keep their cash at a bank) tospur economic growth. Governmental or central bank actions,including interest rate increases, measures to address budgetdeficits, or contrary actions by different governments, as well asdowngrades of sovereign debt, fluctuations in oil andcommodity prices, dramatic changes in currency exchange ratesand geopolitical events (including war and terror attacks) could

negatively affect financial markets generally, increase marketvolatility and reduce the value and liquidity of securities inwhich a Portfolio invests.

Policy and legislative changes in the United States and in othercountries (such as the UK referendum vote to exit the EU, asfurther discussed below) may also contribute to decreasedliquidity and increased volatility in the financial markets.Political turmoil within the U.S. and abroad may also impactthe Portfolios. Although the U.S. government has honored itscredit obligations, it remains possible that the U.S. coulddefault on its obligations. While it is impossible to predict theconsequences of such an unprecedented event, it is likely that adefault by the U.S. would be highly disruptive to the U.S. andglobal securities markets and could significantly impair thevalue of the Portfolios’ investments. Similarly, political eventswithin the United States at times have resulted, and may in thefuture result, in a shutdown of government services, whichcould negatively affect the U.S. economy, decrease the value ofmany Portfolio investments, and increase uncertainty in orimpair the operation of the U.S. or other securities markets.

The U.S. is also considering significant increases ininfrastructure and national defense spending which, coupledwith lower federal taxes, could lead to increased governmentborrowing and higher interest rates. The equity and debtmarkets may react strongly to this possibility, which couldincrease volatility, especially if the market’s expectations forsuch changes are not borne out.

Economies and financial markets throughout the world areincreasingly interconnected. Economic, financial or politicalevents, trading and tariff arrangements, terrorism, naturaldisasters, public health emergencies (including pandemics andepidemics) and other circumstances in one country or regioncould have profound impacts on global economies or markets.As a result, whether or not a Portfolio directly invests insecurities of issuers located in or with significant exposure tothe countries directly affected, the value and liquidity of aPortfolio’s investments may be negatively affected.

In June 2016, voters in the UK approved a referendum to leavethe EU. The UK gave notice in March 2017 of its withdrawalfrom the EU and commenced negotiations on the terms ofwithdrawal. An agreement was reached, and the UK left the EUon January 31, 2020, with a transition period during which theparties will negotiate their future relationship currently set toend on December 31, 2020. There is significant marketuncertainty regarding Brexit’s ramifications, and the range andpotential implications of possible political, regulatory,economic, and market outcomes are difficult to predict.Political events, including nationalist unrest in Europe anduncertainties surrounding the sovereign debt of a number ofEU countries and the viability of the EU itself, also may causemarket disruptions. If one or more countries leave the EU or



the EU dissolves, the world’s securities markets likely will besignificantly disrupted. Moreover, the uncertainty about theramifications of Brexit may cause significant volatility and/ordeclines in the value of the Euro and British pound. Brexit (andin particular a hard Brexit, i.e., an exit in which the UK leavesnot only the EU, but also the EU single market and the EUcustoms union, and without agreements on trade, finance andother key elements) may cause significant market volatility andilliquidity, currency fluctuations, deterioration in economicactivity, a decrease in business confidence, and increasedlikelihood of a recession in the UK. This may increaseredemptions from Portfolios that hold impacted securities, orcause the value of a Portfolio’s securities that are economicallytied to the UK or EU to decline. Additionally, it is possible thatmeasures could be taken to revote on the issue of Brexit, or thatportions of the UK could seek to separate and remain a part ofthe EU. Market factors, such as the demand for particularportfolio securities, may cause the price of certain portfoliosecurities to fall while the price of other securities rise orremain unchanged.

MUNICIPAL AND RELATED INSTRUMENTS. Municipalinstruments include debt obligations issued by or on behalf ofstates, territories and possessions of the United States and theirpolitical subdivisions, agencies, authorities andinstrumentalities. Municipal instruments include both“general” and “revenue” bonds and may be issued to obtainfunds for various public purposes. General obligations aresecured by the issuer’s pledge of its full faith, credit and taxingpower. Revenue obligations are payable only from the revenuesderived from a particular facility or class of facilities. In somecases, revenue bonds also are payable from the proceeds of aspecial excise or other specific revenue source such as leasepayments from the user of a facility being financed.

Some municipal instruments, known as private activity bonds,are issued to finance projects for private companies. Privateactivity bonds are usually revenue obligations since theytypically are payable by the private user of the facilities financedby the bonds.

Municipal instruments also include “moral obligation” bonds,municipal leases, certificates of participation and asset-backedsecurities such as custodial receipts. Moral obligation bonds aresupported by a moral commitment but not a legal obligation of astate or municipality. Municipal leases and participationcertificates present the risk that the state or municipality involvedwill not appropriate the monies to meet scheduled payments onan annual basis. Custodial receipts represent interests inmunicipal instruments held by a trustee or custodian.

Certain municipal obligations are issued with interest rates thatadjust periodically. Such municipal floating-rate debtobligations are generally indexed to the London InterbankOffer Rate, the Securities Industry and Financial Market

Association index, the Consumer Price Index or other indices.Municipal floating-rate debt obligations include, but are notlimited to, municipal floating rate notes, floating-rate notesissued by tender option bond trusts, auction rate preferredsecurities, synthetic floating-rate securities (e.g., a fixed-rateinstrument that is subject to a swap agreement converting afixed rate to a floating rate) and other municipal instrumentswith floating interest rates (such as variable rate demandpreferred shares and variable rate term preferred shares).

INVESTMENT STRATEGY. To the extent consistent with itsinvestment objective and principal investment strategies, eachPortfolio may invest from time to time in municipalinstruments or other securities issued by state and localgovernmental bodies. Generally, this will occur when the yieldof municipal instruments, on a pre-tax basis, is comparable tothat of other permitted short-term taxable investments.Dividends paid by the Portfolios on such investments will betaxable to shareholders.

SPECIAL RISKS. Municipal instruments may be backed by lettersof credit, insurance or other forms of credit enhancementissued by foreign and domestic banks, insurance companiesand other financial institutions. If the credit quality of thesebanks and financial institutions declines, a Portfolio couldsuffer a loss to the extent that the Portfolio is relying upon thiscredit support. Foreign institutions can present special risksrelating to higher transaction and custody costs, the impositionof additional taxes by foreign governments, less completefinancial information, less market liquidity, more marketvolatility and political instability. Foreign banks, insurancecompanies and financial institutions may be subject to lessstringent reserve requirements, and to different accounting,auditing and recordkeeping requirements than U.S. banks.

In addition, a single enhancement provider may provide creditenhancement to more than one of a Portfolio’s investments.Having multiple securities credit enhanced by the sameenhancement provider will increase the adverse effects on thePortfolio that are likely to result from a downgrading of, or adefault by, such an enhancement provider. Adversedevelopments in the banking or bond insurance industries alsomay negatively affect a Portfolio. Bond insurers that providecredit enhancement for large segments of the fixed-incomemarkets, particularly the municipal bond market, may be moresusceptible to being downgraded or defaulting duringrecessions or similar periods of economic stress. Municipalbonds may be covered by insurance that guarantees timelyinterest payments and repayment of principal on maturity. If abond’s insurer fails to fulfill its obligations or loses its creditrating, the value of the bond could drop. Insurance does notprotect a Portfolio or its shareholders from losses caused bydeclines in a bond’s market value.



Also, an insurance company’s exposure to securities involvingsubprime mortgages may cause a municipal bond insurer’srating to be downgraded or may cause the bond insurer tobecome insolvent, which may affect the prices and liquidity ofmunicipal obligations insured by the insurance company.

In addition, when a substantial portion of a Portfolio’s assets isinvested in instruments which are used to finance facilitiesinvolving a particular industry, whose issuers are in the samestate or which otherwise are related, there is a possibility that aneconomic, business or political development affecting oneinstrument would likewise affect the related instrument.

In recent periods an increasing number of municipal issuershave defaulted on obligations, been downgraded orcommenced insolvency proceedings. Any of these effects couldhave a significant impact on the prices of some or all of themunicipal instruments held by a Portfolio.

OPERATIONAL RISK. The Investment Adviser to the Portfoliosand other Portfolio service providers may be subject tooperational risk and may experience disruptions and operatingerrors. In particular, these errors or failures in systems andtechnology, including operational risks associated with relianceon third party service providers, may adversely affect aPortfolio’s ability to calculate its NAV in a timely manner,including over a potentially extended period. While serviceproviders are required to have appropriate operational riskmanagement policies and procedures in place, their methods ofoperational risk management may differ from those of aPortfolio in the setting of priorities, the personnel andresources available or the effectiveness of relevant controls. TheInvestment Adviser, through its monitoring and oversight ofservice providers, seeks to ensure that service providers takeappropriate precautions to avoid and mitigate risks that couldlead to disruptions and operating errors. However, it is notpossible for the Investment Adviser or other Portfolio serviceproviders to identify all of the operational risks that may affecta Portfolio or to develop processes and controls to completelyeliminate or mitigate their occurrence or effects.

PREPAYMENT (OR CALL) RISK (principal risk for each Portfolio) isthe risk that prepayment of the underlying mortgages or othercollateral of some fixed-income securities may result in adecreased rate of return and a decline in value of thosesecurities. As interest rates fall and certain obligations are paidoff by obligors more quickly than originally anticipated, aPortfolio may invest the proceeds in securities with lower yields.

RECENT MARKET EVENTS. Periods of unusually high financialmarket volatility and restrictive credit conditions, at timeslimited to a particular sector or geographic area, have occurredin the past and may be expected to recur in the future. Somecountries, including the United States, have adopted or have

signaled protectionist trade measures, relaxation of thefinancial industry regulations that followed the financial crisis,and/or reductions to corporate taxes. The scope of these policychanges is still developing, but the equity and debt markets mayreact strongly to expectations of change, which could increasevolatility, particularly if a resulting policy runs counter to themarket’s expectations. The outcome of such changes cannot beforeseen at the present time. In addition, geopolitical and otherrisks, including environmental and public health risks, may addto instability in the world economy and markets generally. As aresult of increasingly interconnected global economies andfinancial markets, the value and liquidity of a Portfolio’sinvestments may be negatively affected by events impacting acountry or region, regardless of whether the Portfolio invests inissuers located in or with significant exposure to such countryor region.

Recent events are impacting the securities markets. A recentoutbreak of respiratory disease caused by a novel coronaviruswas first detected in December 2019 and has spreadinternationally. The outbreak and efforts to contain its spreadhave resulted in closing borders and quarantines, restrictinginternational and domestic travel, enhanced health screenings,cancellations, disrupted supply chains and customer activity,responses by businesses (including changes to operations andreducing staff), and have produced general concern anduncertainty. The impact of the coronavirus pandemic, andother epidemics and pandemics that may arise in the future,could adversely affect national and global economies,individual companies and the market in general in a mannerand for a period of time that cannot be foreseen at the presenttime. Health crises caused by the recent outbreak may heightenother pre-existing political, social and economic risks in acountry or region. Governmental authorities and regulatorsthroughout the world, such as the U.S. Federal Reserve, have inthe past responded to major economic disruptions withchanges to fiscal and monetary policy, including but not lim-ited to, direct capital infusions, new monetary programs, anddramatically lower interest rates. Certain of those policychanges are being implemented in response to the coronavirusoutbreak. Such policy changes may adversely affect the value,volatility and liquidity of dividend and interest paying secu-rities. In certain cases, an exchange or market may close or issuetrading halts on either specific securities or even the entiremarket, which may result in a Portfolio being, among otherthings, unable to buy or sell certain securities or financialinstruments or to accurately price its investments. In the eventof a pandemic or an outbreak, there can be no assurance thatthe Portfolios and their service providers will be able to main-tain normal business operations for an extended period of timeor will not lose the services of key personnel on a temporary orlong-term basis due to illness or other reasons. A pandemic or



disease could also impair the information technology and otheroperational systems upon which a Portfolio’s investmentadviser relies, and could otherwise disrupt the ability of thePortfolio’s service providers to perform essential tasks.Although multiple asset classes may be affected by a marketdisruption, the duration and effects may not be the same for alltypes of assets. To the extent a Portfolio may overweight itsinvestments in certain countries, companies, industries ormarket sectors, such position will increase the Portfolio’sexposure to risk of loss from adverse developments affectingthose countries, companies, industries or sectors. These con-ditions could result in a Portfolio’s inability to achieve itsinvestment objectives, cause the postponement of recon-stitution or rebalance dates for benchmark indices, adverselyaffect the prices and liquidity of the securities and otherinstruments in which a Portfolio invests, negatively impacting aPortfolio’s performance, and cause losses on your investmentsin a Portfolio. You should also review this prospectus and theSAI to understand each Portfolio’s discretion to implementtemporary defensive measures, as well as the circumstances inwhich a Portfolio may satisfy redemption requests in-kind.

REPURCHASE AGREEMENTS (principal strategy for eachPortfolio). Repurchase agreements involve the purchase ofsecurities by a Portfolio subject to the seller’s agreement torepurchase them at a mutually agreed upon date and price.

INVESTMENT STRATEGY. To the extent consistent with itsinvestment objective and principal investment strategies, eachPortfolio may enter into repurchase agreements with domesticand foreign financial institutions such as banks and broker-dealers that are deemed to be creditworthy by the InvestmentAdviser. Although the securities subject to a repurchaseagreement may have maturities exceeding one year, settlementof the agreement generally will not occur more than one yearafter a Portfolio acquires the securities.

SPECIAL RISKS. In the event of a default, a Portfolio will suffer aloss to the extent that the proceeds from the sale of theunderlying securities and other collateral are less than therepurchase price and the Portfolio’s costs associated with delayand enforcement of the repurchase agreement. In addition, inthe event of bankruptcy, a Portfolio could suffer additionallosses if a court determines that the Portfolio’s interest in thecollateral is unenforceable by the Portfolio. If a Portfolio entersinto a repurchase agreement with a foreign financial institution,it may be subject to the same risks associated with foreigninvestments (see “Foreign Investments” on page 30).

The Portfolios intend to enter into transactions withcounterparties that are creditworthy at the time of thetransactions. There is always the risk that the InvestmentAdviser’s analysis of creditworthiness is incorrect or maychange due to market conditions. To the extent that a Portfolio

focuses its transactions with a limited number ofcounterparties, it will be more susceptible to the risks associatedwith one or more counterparties.

With respect to collateral received in repurchase transactions orother investments, a Portfolio may have significant exposure tothe financial services and mortgage markets. Such exposure,depending on market conditions, could have a negative impacton the Portfolio, including minimizing the value of anycollateral.

STRIPPED SECURITIES. These securities are issued by the U.S.government (or an agency, instrumentality or a sponsoredenterprise), foreign governments, banks and other issuers.

They entitle the holder to receive either interest payments orprincipal payments that have been “stripped” from a debtobligation. These obligations include stripped mortgage-backedsecurities, which are derivative multi-class mortgage securities.

The Treasury Department has facilitated transfers of ownershipof zero coupon securities by accounting separately for thebeneficial ownership of particular interest coupon andprincipal payments on Treasury securities through the FederalReserve book-entry record-keeping system. The Federal Reserveprogram as established by the Treasury Department is knownas “Separate Trading of Registered Interest and Principal ofSecurities” or “STRIPS.” Under the STRIPS program, aPortfolio will be able to have its beneficial ownership of zerocoupon securities recorded directly in the book-entry record-keeping system in lieu of having to hold certificates or otherevidences of ownership of the underlying U.S. Treasurysecurities.

INVESTMENT STRATEGY. To the extent consistent with theirinvestment objectives and strategies, the Portfolios maypurchase stripped securities, including securities registered inthe STRIPS program.

SPECIAL RISKS. Stripped securities are very sensitive to changesin interest rates and to the rate of principal prepayments. Arapid or unexpected change in either interest rates or principalprepayments could depress the price of stripped securities heldby the Portfolios and adversely affect a Portfolio’s investmentperformance.

STRUCTURED SECURITIES. The value of such securities isdetermined by reference to changes in the value of specificcurrencies, interest rates, commodities, securities, indices orother financial indicators (the “Reference”) or the relativechange in two or more References. The interest rate or theprincipal amount payable upon maturity or redemption maybe increased or decreased depending upon changes in theapplicable Reference. Examples of structured securities include,but are not limited to, asset-backed commercial paper,



structured notes and other debt obligations where the principalrepayment at maturity is determined by the value of a specifiedsecurity or securities index.

INVESTMENT STRATEGY. The Portfolios may invest in structuredsecurities to the extent consistent with their investmentobjectives and strategies.

SPECIAL RISKS. Structured securities present additional risk thatthe interest paid to a Portfolio on a structured security will beless than expected. The terms of some structured securities mayprovide that in certain circumstances no principal is due atmaturity and, therefore, a Portfolio could suffer a total loss ofits investment. Structured securities may be positively ornegatively indexed, so that appreciation of the Reference mayproduce an increase or decrease in the interest rate or value ofthe security at maturity. In addition, changes in the interestrates or the value of the security at maturity may be a multipleof changes in the value of the Reference. Consequently,structured securities may entail a greater degree of market riskthan other types of securities. Structured securities also may bemore volatile, less liquid and more difficult to accurately pricethan less complex securities due to their derivative nature.

TEMPORARY INVESTMENTS. For capital preservation andliquidity, each Portfolio may have a greater concentration inshort-term securities, including investing up to all of its assetsin overnight securities, which may result in a reduction of aPortfolio’s yield.

Although the Investment Adviser has the ability to taketemporary positions, it may choose not to do so for a variety ofreasons, even during volatile market conditions.

U.S. GOVERNMENT OBLIGATIONS (principal risk for eachPortfolio). These instruments include U.S. Treasury obligations,such as bills, notes and bonds, which generally differ only interms of their interest rates, maturities and time of issuance.They also include obligations issued or guaranteed by the U.S.government or by its agencies, instrumentalities or sponsoredenterprises. Securities guaranteed as to principal and interest bythe U.S. government or by its agencies, instrumentalities orsponsored enterprises are deemed to include (a) securities forwhich the payment of principal and interest is backed by anirrevocable letter of credit issued by the U.S. government or byan agency, instrumentality or sponsored enterprise thereof and(b) participations in loans made to foreign governments ortheir agencies that are so guaranteed. U.S. treasury obligationsalso include floating rate public obligations of the U.S.Treasury.

INVESTMENT STRATEGY. To the extent consistent with itsinvestment objective and strategies, each Portfolio may investin a variety of U.S. Treasury obligations and in otherobligations issued or guaranteed by the U.S. government or by

its agencies, instrumentalities or sponsored enterprises.

SPECIAL RISKS. Not all U.S. government obligations carry thesame credit support. Although many U.S. governmentsecurities are issued by entities chartered or sponsored by Actsof Congress, such as the Federal National Mortgage Association(“Fannie Mae”), the Federal Home Loan MortgageCorporation (“Freddie Mac”) and the Federal Home LoanBanks, such securities are neither issued nor guaranteed by theU.S. Treasury and, therefore, are not backed by the full faithand credit of the United States. Some, such as those of theGovernment National Mortgage Association (“Ginnie Mae”),are supported by the full faith and credit of the U.S. Treasury,although this guarantee applies only to principal and interestpayments and does not apply to losses resulting from declinesin the market value of these securities. Other obligations, suchas those of the Federal Home Loan Banks, are supported by theright of the issuer to borrow from the U.S. Treasury; and othersare supported by the discretionary authority of the U.S.government to purchase the agency’s obligations. Still othersare supported only by the credit of the instrumentality orsponsored enterprise. The maximum potential liability of theissuers of some U.S. government securities may greatly exceedtheir current resources, including their legal right to supportfrom the U.S. Treasury. It is possible that these issuers will nothave the funds to meet their payment obligations in the future.No assurance can be given that the U.S. government wouldprovide financial support to its agencies, instrumentalities orsponsored enterprises if it is not obligated to do so by law. Inaddition, the secondary market for certain participations inloans made to foreign governments or their agencies may belimited.

An agency of the U.S. government has placed Fannie Mae andFreddie Mac into conservatorship, a statutory process with theobjective of returning the entities to normal businessoperations. It is unclear what effect this conservatorship willhave on the securities issued or guaranteed by Fannie Mae orFreddie Mac. As a result, these securities are subject to morecredit risk than U.S. government securities that are supportedby the full faith and credit of the United States (e.g., U.S.Treasury bonds). To the extent a Portfolio invests in debtinstruments or securities of non-U.S. government entities thatare backed by the full faith and credit of the United States,pursuant to the FDIC Debt Guarantee Program (the “DebtGuarantee Program”) or other similar programs, there is apossibility that the guarantee provided under the DebtGuarantee Program or other similar programs may bediscontinued or modified at a later date.

Floating rate public obligations of the U.S. Treasury (“FloatingRate Notes” or “FRNs”) have interest rates that adjustperiodically. FRNs’ floating interest rates may be higher or



lower than the interest rates of fixed-rate bonds of comparablequality with similar maturities. Securities with floating rates canbe less sensitive to interest rate changes than securities withfixed interest rates, but may decline in value and negativelyimpact the Portfolio, particularly if changes in prevailinginterest rates are more frequent or sudden than the rate changesfor the FRNs, which only occur periodically (see “Variable andFloating Rate Instruments” below).

VARIABLE AND FLOATING RATE INSTRUMENTS (principal riskfor each Portfolio). Variable and floating rate instruments haveinterest rates that periodically are adjusted either at set intervalsor that float at a margin tied to a specified index rate. Theseinstruments include floating rate Treasury obligations, variableamount master demand notes and long-term variable andfloating rate bonds (sometimes referred to as “Put Bonds”)where a Portfolio obtains at the time of purchase the right toput the bond back to the issuer or a third party at par at aspecified date.

INVESTMENT STRATEGY. Each Portfolio may invest in variable orfloating rate instruments to the extent consistent with itsinvestment objective and strategies.

SPECIAL RISKS. Variable and floating rate instruments aresubject to many of the same risks as fixed rate instruments,particularly credit risk and default risk, which could impedetheir value. Because there is no active secondary market forcertain variable and floating rate instruments, they may bemore difficult to sell if the issuer defaults on its paymentobligations or during periods when the Portfolios are notentitled to exercise their demand rights. As a result, thePortfolios could suffer a loss with respect to these instruments.In addition, variable and floating rate instruments are subjectto changes in value based on changes in market interest rates orchanges in the issuer’s or guarantor’s creditworthiness. Inaddition, there may be a lag between an actual change in theunderlying interest rate benchmark and the reset time for aninterest payment of a variable or floating instrument, whichcould harm or benefit a Portfolio, depending on the interestrate environment or other circumstances. In a rising interestrate environment, for example, a floating or variable rateinstrument that does not reset immediately would prevent aPortfolio from taking full advantage of rising interest rates in atimely manner.

In 2017, the FCA warned that LIBOR may cease to be availableor appropriate for use by 2021. The unavailability orreplacement of LIBOR may affect the value, liquidity or return

on certain Portfolio investments and may result in costsincurred in connection with closing out positions and enteringinto new trades. Any pricing or adjustments to a Portfolio’sinvestments resulting from a substitute reference rate mayadversely affect the Portfolio’s performance and/or NAV (see“LIBOR Transition” above).

WHEN-ISSUED SECURITIES, DELAYED DELIVERY TRANSACTIONS

AND FORWARD COMMITMENTS. A purchase of “when-issued”securities refers to a transaction made conditionally because thesecurities, although authorized, have not yet been issued. Adelayed delivery or forward commitment transaction involves acontract to purchase or sell securities for a fixed price at afuture date beyond the customary settlement period.

INVESTMENT STRATEGY. Each Portfolio may purchase or sellsecurities on a when-issued, delayed delivery or forwardcommitment basis. Although the Portfolios generally wouldpurchase securities in these transactions with the intention ofacquiring the securities, the Portfolios may dispose of suchsecurities prior to settlement if the Investment Adviser deems itappropriate to do so.

SPECIAL RISKS. Purchasing securities on a when-issued, delayeddelivery or forward commitment basis involves the risk that thevalue of the securities may decrease by the time they actuallyare issued or delivered. Conversely, selling securities in thesetransactions involves the risk that the value of the securitiesmay increase by the time they actually are issued or delivered.Therefore, these transactions may have a leveraging effect on aPortfolio, making the value of an investment in the Portfoliomore volatile and increasing the Portfolio’s overall investmentexposure. These transactions also involve the risk that thecounterparty may fail to deliver the security or cash on thesettlement date. If this occurs, a Portfolio may lose both theinvestment opportunity for the assets it set aside to pay for thesecurity and any gain in the security’s price.

OTHER SECURITIES. Additionally, the Portfolios may purchaseother types of securities or instruments similar to thosedescribed in these sections if otherwise consistent with thePortfolios’ investment objectives and strategies. You shouldcarefully consider the risks discussed in these sections beforeinvesting in a Portfolio.

The Portfolios may invest in other securities and are subject tofurther restrictions and risks that are described in the SAI.Additional information about the Portfolios, their investmentsand related risks can also be found in “Investment Objectivesand Strategies” in the SAI.



F I N A N C I A L H I G H L I G H T S

THE FINANCIAL HIGHLIGHTS TABLES ARE INTENDED TO HELP YOU UNDERSTAND THE FINANCIAL

PERFORMANCE OF A PORTFOLIO’S WILLIAMS CAPITAL SHARES FOR THE PAST FIVE YEARS (OR, IF

SHORTER, THE PERIOD OF THE PORTFOLIO’S OPERATIONS). BECAUSE THE WILLIAMS CAPITAL

SHARES OF THE PRIME OBLIGATIONS PORTFOLIO HAD NOT COMMENCED OPERATIONS AS OF

NOVEMBER 30, 2019, INFORMATION IS SHOWN FOR THE PORTFOLIO’S SHARES CLASS, WHICH IS

OFFERED IN A SEPARATE PROSPECTUS.

Certain information reflects the financial results for a single Williams Capital Share. The total returns in

the tables represent the rate that an investor would have earned (or lost) on an investment in Shares of

the Prime Obligations Portfolio and Williams Capital Shares of the U.S. Government Select Portfolio

held for the entire period (assuming reinvestment of all dividends and distributions), and, with respect

to the Prime Obligations Portfolio, do not reflect the effect of the Williams Capital Shares’ different

expenses. The information for the fiscal year ended November 30, 2019 has been derived from

financial statements that have been audited by Deloitte & Touche LLP, an independent registered

public accounting firm, whose reports, along with the Portfolios’ financial statements, are included in

the Portfolios’ annual reports. Information for fiscal years prior to November 30, 2017 was audited

by the Portfolios’ former independent registered public accounting firm. Copies of the semiannual and

annual report are available upon request and without charge.



F I N A N C I A L H I G H L I G H T S FOR THE FISCAL YEARS ENDED NOVEMBER 30,

P R I M E O B L I G A T I O N S P O R T F O L I O S H A R E S

Selected per share data 2019 2018 2017 2016 2015

Net Asset Value, Beginning of Year $1.0000 $1.0001 $1.0002 $1.0000(1) $1.00

INCOME FROM INVESTMENT OPERAT IONS:

Net investment income 0.0231 0.0190(2) 0.0099 0.0040(2) —(3)

Net realized and unrealized gains (losses) 0.0002 (0.0004) (0.0001) 0.0006 —(3)

Total from Investment Operations 0.0233 0.0186 0.0098 0.0046 —

LESS DISTR IBUT IONS PAID :

From net investment income (0.0231) (0.0187) (0.0099) (0.0044) —(3)

From net realized gains — — —(4) — —

Total Distributions Paid (0.0231) (0.0187) (0.0099) (0.0044) —

Net Asset Value, End of Year $1.0002 $1.0000 $1.0001 $1.0002 $1.00

Total Return(5) 2.36% 1.88% 0.99% 0.46% 0.06%

SUPPLEMENTAL DATA AND RAT IOS :

Net assets, in thousands, end of year $4,452,853 $3,011,041 $2,543,262 $1,711,024 $3,610,101

Ratio of average net assets of:

Expenses, net of waivers, reimbursements and credits 0.15% 0.15% 0.15% 0.15% 0.15%

Expenses, before waivers, reimbursements and credits 0.16% 0.17% 0.17% 0.17% 0.17%

Net investment income, net of waivers, reimbursements and credits 2.27% 1.90% 1.01% 0.40% 0.06%

Net investment income, before waivers, reimbursements and credits 2.26% 1.88% 0.99% 0.38% 0.04%

(1) Transacted at two decimals until October 11, 2016.

(2) Net investment income for the year ended was calculated using the average shares outstanding method.

(3) Per share amounts from net investment income, net realized and unrealized gains (losses) and distributions paid from net investment income were less than $0.01per share.

(4) Per share amount from distributions paid from net realized gains was less than $0.0001 per share.

(5) Assumes investment at net asset value at the beginning of the year, reinvestment of all dividends and distributions, and a complete redemption of the investment atnet asset value at the end of the year.



F I N A N C I A L H I G H L I G H T S FOR THE FISCAL YEARS ENDED NOVEMBER 30,

U . S . G O V E R N M E N T S E L E C T P O R T F O L I O W I L L I A M S C A P I T A L

Selected per share data 2019 2018 2017 2016 2015

Net Asset Value, Beginning of Year $1.00 $1.00 $1.00 $1.00 $1.00

INCOME (LOSS) FROM INVESTMENT OPERAT IONS:

Net investment income 0.02 0.02 0.01 —(1) —(1)

Net realized gains (losses)(1) — — — — —

Total from Investment Operations 0.02 0.02 0.01 — —

LESS DISTR IBUT IONS PAID :

From net investment income (0.02) (0.02) (0.01) —(1) —(1)

From net realized gains —(1) —(1) — — —

Total Distributions Paid (0.02) (0.02) (0.01) — —

Net Asset Value, End of Year $1.00 $1.00 $1.00 $1.00 $1.00

Total Return(2) 2.13% 1.58% 0.66% 0.20% 0.01%

SUPPLEMENTAL DATA AND RAT IOS :

Net assets, in thousands, end of period $455,839 $216,367 $472,479 $474,161 $213,987

Ratio to average net assets of:

Expenses, net of waivers, reimbursements and credits 0.20% 0.20% 0.20% 0.20% 0.12%

Expenses, before waivers, reimbursements and credits 0.21% 0.21% 0.21% 0.21% 0.21%

Net investment income, net of waivers, reimbursements and credits 2.06% 1.54% 0.66% 0.21% 0.01%

Net investment income (loss), before waivers, reimbursements and credits 2.05% 1.53% 0.65% 0.20% (0.08)%

(1) Per share amounts from net investment income, net realized gains (losses) and distributions paid from net investment income and net realized gains were less than$0.01 per share.

(2) Assumes investment at net asset value at the beginning of the year, reinvestment of all dividends and distributions, and a complete redemption of the investment atnet asset value at the end of the year.



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811-03605©2020 Northern Institutional Funds

Siebert Williams Shank & Co., LLC 100 Wall Street, 18th Floor New York, NY 10005Siebertwilliams.com

FOR SHAREHOLDER INQUIRIES OR TO OBTAIN INFORMATION:

For Orders: 800-637-1380

For Questions: 866-926-3863

BY T E L E P H O N E


BY M A I L

The Portfolio’s documents are available online and may be downloaded from:

n The EDGAR database on the SEC’s web site at sec.gov (text only)

n Northern Institutional Funds website at northerntrust.com/institutional

O N T H E I N T E R N E T

ANNUAL/SEMIANNUAL REPORTS AND STATEMENT OF ADDITIONAL INFORMATION (“SAI”)Additional information about the Portfolios’ investments is available in the Portfolios’ annual and semiannual reports to shareholders. In the Portfolios’ annual reports, you will find a discussion of the market conditions and investment strategies that significantly affected the Portfolios’ performance during the last fiscal year.

Additional information about the Portfolios and their policies is also available in the Portfolios’ SAI. The SAI is incorporated by reference into this Prospectus (and is legally considered part of this Prospectus).

The Portfolios’ annual and semiannual reports and the SAI are available free upon request by calling the Northern Institutional Funds Center at 800-637-1380 or by sending an e-mail request to: [email protected]. The SAI and other information are available from a financial intermediary (such as a broker-dealer or bank) through which the Portfolios’ shares may be purchased or sold.

Reports and other information about Northern Institutional Funds are available on the Edgar database on the SEC’s internet site at http://www.sec.gov. You may also obtain copies of Northern Institutional Funds documents, after paying a duplicating fee, by sending your electronic request to: publicinfo @sec.gov.


NIF PRO WC (4/20)

Documents

PROSPECTUS AND STATEMENT OF ADDITIONAL …...prospectus and statement of additional information (“sai”) supplement northern institutional funds money market portfolios — williams