UBS Series Funds...UBS Series Funds November 25, 2020 Supplement to the Prospectus dated August 28,...

UBS Series FundsMarch 24, 2021

Supplement to the prospectuses (each, a “Prospectus” and together, the “Prospectuses”) referencedbelow, as may have been supplemented.

Dear Investor:

The purpose of this supplement is to update information contained in Appendix A to the Prospectuses for each ofthe series of UBS Series Funds noted below (the “funds”).

The Securities Industry and Financial Markets Association (“SIFMA”) has changed its “early close” recommendationschedule. SIFMA no longer recommends an early close on the afternoon before Good Friday; therefore, on April 1,2021 (the business day prior to Good Friday), UBS Select Government Institutional Fund, UBS Select Treasury Institu-tional Fund, UBS Select Government Preferred Fund, UBS Select Treasury Preferred Fund, UBS Select GovernmentInvestor Fund, UBS Select Treasury Investor Fund, UBS Prime Reserves Fund, UBS Prime Preferred Fund and UBSPrime Investor Fund will not advance the final time by which orders to buy or sell shares must be received by thetransfer agent and expect to be open for normal business hours as elsewhere described in the Prospectuses. Allfunds will be closed for business on April 2, 2021, in accordance with the observance of Good Friday by the NewYork Stock Exchange.

Effective immediately, the Prospectuses are hereby revised as follows:

Appendix A to each of the Prospectuses is hereby updated accordingly to remove the reference to April 1, 2021,under the column captioned “Early close.”

Fund NameDate ofProspectus

UBS Series Funds—UBS Select Prime Institutional Fund, UBS Select Treasury Institutional Fund,UBS Select Government Institutional Fund, UBS Select ESG Prime Institutional Fund, UBS SelectPrime Preferred Fund, UBS Select Government Preferred Fund, UBS Select Treasury PreferredFund, UBS Select ESG Prime Preferred Fund, UBS Select Prime Investor Fund, UBS SelectGovernment Investor Fund, UBS Select Treasury Investor Fund, UBS Select ESG Prime InvestorFund, UBS Prime Reserves Fund, UBS Tax-Free Reserves Fund, UBS Prime Preferred Fund, UBSTax-Free Preferred Fund, UBS Prime Investor Fund and UBS Tax-Free Investor Fund

August 28, 2020

PLEASE BE SURE TO RETAIN THIS IMPORTANT INFORMATION FOR FUTURE REFERENCE.

ZS-1099

UBS Series FundsFebruary 24, 2021

Supplement to the Prospectus dated August 28, 2020, as supplemented.

Includes:‰ UBS Select ESG Prime Investor Fund

Dear Investor,

The purpose of this supplement is to update certain information contained in the Prospectus for UBS Select ESGPrime Investor Fund regarding the extension of the voluntary fee waiver through May 31, 2021. This disclosurechange will become effective on March 1, 2021.

The Prospectus is hereby supplemented as shown below.

The section captioned “Management” and sub-captioned “Advisory and administration fees” on page 44of the Prospectus is revised by replacing the first sentence of the fourth paragraph of that section in itsentirety with the following:

UBS AM will voluntarily waive its 0.10% master fund level fee in order to voluntarily reduce UBS Select ESG PrimeInvestor Fund’s expenses by 0.10% until May 31, 2021.


ZS-1093

UBS Series FundsJanuary 27, 2021



Dear Investor,

The purpose of this supplement is to update certain information contained in the Prospectus for UBS Select ESGPrime Investor Fund regarding the extension of the voluntary fee waiver through February 28, 2021. This disclosurechange will become effective on February 1, 2021.



UBS AM will voluntarily waive its 0.10% master fund level fee in order to voluntarily reduce UBS Select ESG PrimeInvestor Fund’s expenses by 0.10% until February 28, 2021.


ZS-1090

UBS Series FundsDecember 29, 2020



Dear Investor,

The purpose of this supplement is to update certain information contained in the Prospectus for UBS Select ESGPrime Investor Fund regarding the extension of the voluntary fee waiver through January 31, 2021. This disclosurechange will become effective on January 1, 2021.



UBS AM will voluntarily waive its 0.10% master fund level fee in order to voluntarily reduce UBS Select ESG PrimeInvestor Fund’s expenses by 0.10% until January 31, 2021.


ZS-1085

UBS Series FundsNovember 25, 2020

Supplement to the Prospectus dated August 28, 2020.


Dear Investor,

The purpose of this supplement is to update certain information contained in the Prospectus for UBS Select ESGPrime Investor Fund regarding the extension of the voluntary fee waiver through December 31, 2020. This disclosurechange will become effective on December 1, 2020.



UBS AM will voluntarily waive its 0.10% master fund level fee in order to voluntarily reduce UBS Select ESG PrimeInvestor Fund’s expenses by 0.10% until December 31, 2020.


ZS-1078

Money Market FundsProspectus | August 28, 2020

Includes:• UBS Select Prime Investor Fund: SPIXX• UBS Select Government Investor Fund: SGEXX• UBS Select Treasury Investor Fund: STRXX• UBS Select ESG Prime Investor Fund: SEIXX

As with all mutual funds, the Securities and Exchange Commission has not approved or disapproved thefunds’ shares or determined whether this prospectus is complete or accurate. To state otherwise is acrime.

Not FDIC Insured. May lose value. No bank guarantee.

Contents

The fundsWhat every investor should know about the funds

Fund summariesUBS Select Prime Investor Fund 3UBS Select Government Investor Fund 9UBS Select Treasury Investor Fund 14UBS Select ESG Prime Investor Fund 20

More information about the funds 26

Your investmentInformation for managing your fund accountManaging your fund account 35—Buying shares 35—Selling shares 37—Exchanging shares 39—Transfer of account limitations 39—Additional information about your account 40—Market timing 42—Pricing and valuation 42

Additional informationAdditional important information about the fundsManagement 44Dividends and taxes 45Disclosure of portfolio holdings and other information 49Financial highlights 51Appendix A: Additional information regarding purchases and redemptions 56Where to learn more about the funds Back cover

Please find the UBS family of funds privacy notice on page 57. Please find the UBS Asset Managementbusiness continuity planning overview on page 59.

The funds are not a complete or balanced investment program.

2

UBS Select Prime Investor FundFund summary

Investment objectiveMaximum current income consistent with liquidity and the preservation of capital.

Fees and expenses of the fundThese tables describe the fees and expenses that you may pay if you buy and hold shares of the fund.

Shareholder fees (fees paid directly from your investment)

Maximum front-end sales charge (load) imposed on purchases None

Maximum deferred sales charge (load) None

Annual fund operating expenses (expenses that you pay each year as a percentage of the value of yourinvestment)*

Management fees 0.20%

Distribution (12b-1) fees 0.25

Other expenses 0.12

Shareholder servicing fee 0.10

Miscellaneous expenses 0.02

Total annual fund operating expenses 0.57

Fee waiver/expense reimbursement1 0.07

Total annual fund operating expenses after fee waiver and/or expense reimbursement1 0.50

* The fund invests in securities through an underlying master fund, Prime Master Fund. This table reflects the direct expenses of the fund and its share ofexpenses of Prime Master Fund, including management fees allocated from Prime Master Fund. Management fees are comprised of investment advisoryand administration fees.

1 The fund and UBS Asset Management (Americas) Inc. (“UBS AM”) have entered into a written fee waiver/expense reimbursement agreement pursuant towhich UBS AM is contractually obligated to waive its management fees and/or reimburse the fund so that the fund’s operating expenses throughAugust 31, 2021 (excluding interest expense, if any, and extraordinary items) would not exceed 0.50%. The fund has agreed to repay UBS AM for anywaived fees/reimbursed expenses to the extent that it can do so over the three years following such waived fees/reimbursed expenses without causing thefund’s expenses in any of those three years to exceed the expense cap. The fee waiver/expense reimbursement agreement may be terminated by thefund’s board at any time and also will terminate automatically upon the expiration or termination of the fund’s contract with UBS AM. Upon terminationof the agreement, however, UBS AM’s three year recoupment rights will survive.

3

ExampleThis example is intended to help you compare the cost of investing in the fund with the cost of investing inother mutual funds. The example assumes that you invest $10,000 in the fund for the time periods indi-cated and then redeem all of your shares at the end of those periods. The example also assumes that yourinvestment has a 5% return each year and that the fund’s operating expenses remain the same.*

Although your actual costs may be higher or lower, based on these assumptions your costs would be:

1 year 3 years 5 years 10 years

UBS Select Prime Investor Fund $51 $176 $311 $707

* Except that the expenses reflect the effects of the fund’s fee waiver/expense reimbursement agreement, including any recoupments, for the first year only.

Principal strategiesPrincipal investmentsThe fund is a money market fund that calculates its net asset value to four decimals (e.g., $1.0000) usingmarket-based pricing. As a result, its share price will fluctuate. The fund seeks to achieve its objective byinvesting in a diversified portfolio of high quality money market instruments of governmental and privateissuers. These may include:

• short-term obligations of the US government and its agencies and instrumentalities;• repurchase agreements;• obligations of issuers in the financial services group of industries;• commercial paper, other corporate obligations and asset-backed securities; and• municipal money market instruments.

Money market instruments generally are short-term debt obligations and similar securities. They also mayinclude longer-term bonds that have variable interest rates or other special features that give them thefinancial characteristics of short-term debt. The fund invests in foreign money market instruments only ifthey are denominated in US dollars. The fund will, under normal circumstances, invest more than 25% ofits total assets in the financial services group of industries.

The fund invests in securities through an underlying master fund. The fund and its corresponding masterfund have the same objective. Unless otherwise indicated, references to the fund include the master fund.

The fund may be subject to the possible imposition of a liquidity fee and/or temporary redemption gateshould certain triggering events occur.

Management processUBS Asset Management (Americas) Inc. (“UBS AM”) acts as the investment advisor. As investment advisor,UBS AM makes the fund’s investment decisions. UBS AM selects money market instruments for the fundbased on its assessment of relative values and changes in market and economic conditions.

4

UBS AM considers safety of principal and liquidity in selecting securities for the fund and thus may not buysecurities that pay the highest yield.

Principal risksAll investments carry a certain amount of risk, and the fund cannot guarantee that it will achieve its invest-ment objective.

You could lose money by investing in the fund. Because the share price of the fund will fluctuate, whenyou sell your shares they may be worth more or less than what you originally paid for them. Also, the fundmay impose a fee upon the sale of your shares or may temporarily suspend your ability to sell shares if thefund’s liquidity falls below required minimums because of market conditions or other factors. An invest-ment in the fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any othergovernment agency. The fund’s sponsor has no legal obligation to provide financial support to the fund,and you should not expect that the sponsor will provide financial support to the fund at any time.

Money market instruments generally have a low risk of loss, but they are not risk-free. The principal riskspresented by an investment in the fund are:

Credit risk: Issuers of money market instruments or financial institutions that have entered into repur-chase agreements with the fund may fail to make payments when due or complete transactions, or theymay become less willing or less able to do so.

Interest rate risk: The value of the fund’s investments generally will fall when interest rates rise, and its yieldwill tend to lag behind prevailing rates. The fund may face a heightened level of interest rate risk due to cer-tain changes in monetary policy, such as certain types of interest rate changes by the Federal Reserve. Duringperiods when interest rates are low or there are negative interest rates, the fund’s yield (and total return) alsomay be low or the fund may be unable to maintain positive returns or minimize the volatility of the fund’snet asset value per share.

Market risk: The risk that the market value of the fund’s investments may fluctuate, sometimes rapidly orunpredictably, as the markets fluctuate, which may affect the fund’s share price. Market risk may affect asingle issuer, industry, or sector of the economy, or it may affect the market as a whole. Moreover, chang-ing market, economic, political and social conditions in one country or geographic region could adverselyimpact market, economic, political and social conditions in other countries or regions.

Liquidity risk: Although the fund invests in a diversified portfolio of high quality instruments, the fund’sinvestments may become less liquid as a result of market developments or adverse investor perception.

Management risk: The risk that the investment strategies, techniques and risk analyses employed by theadvisor may not produce the desired results.

5

Concentration risk: The fund will invest a significant portion of its assets in securities issued by compa-nies in the financial services group of industries, including US banking, non-US banking, broker-dealers,insurance companies, finance companies (e.g., automobile finance) and related asset-backed securities.Accordingly, the fund will be more susceptible to developments that affect those industries than otherfunds that do not concentrate their investments.

Financial services sector risk: Investments of the fund in the financial services sector may be particularlyaffected by economic cycles, business developments, interest rate changes and regulatory changes.

US Government securities risk: There are different types of US government securities with different lev-els of credit risk, including the risk of default, depending on the nature of the particular government sup-port for that security. For example, a US government-sponsored entity, such as Federal National MortgageAssociation (“Fannie Mae”) or Federal Home Loan Mortgage Corporation (“Freddie Mac”), although char-tered or sponsored by an Act of Congress, may issue securities that are neither insured nor guaranteed bythe US Treasury and are therefore riskier than those that are.

Foreign investing risk: The value of the fund’s investments in foreign securities may fall due to adversepolitical, social and economic developments abroad. However, because the fund’s foreign investmentsmust be denominated in US dollars, it generally is not subject to the risk of changes in currency valuations.

Municipal securities risk: Municipal securities are subject to interest rate and credit risks. The ability of amunicipal issuer to make payments and the value of municipal securities can be affected by uncertaintiesin the municipal securities market. Such uncertainties could cause increased volatility in the municipal secu-rities market and could negatively impact the fund’s net asset value and/or the distributions paid by thefund. Municipalities continue to experience difficulties in the current economic and political environment.

PerformanceRisk/return bar chart and tableThe following bar chart and table provide information about the fund’s performance and thus give someindication of the risks of an investment in the fund.

The bar chart shows how the fund’s performance has varied from year to year.

The table that follows the bar chart shows the average annual returns over the various time periods for thefund’s shares.

The fund’s past performance does not necessarily indicate how the fund will perform in the future.

6

UBS Select Prime Investor Fund Annual Total ReturnsTotal return

Calendar Year

0

1

2

3

4%

2019

0.01%

2010

0.01%

2011

0.01%

2012

0.01%

2013 2017

0.01%

2015

0.01%

2014

0.12%

2016

0.74%

2018

1.66%1.97%

Total return January 1 to June 30, 2020: 0.38%Best quarter during years shown—1Q 2019: 0.54%Worst quarters during years shown—1Q, 2Q & 3Q 2010; 1Q 2011: 0.00% (Actual total returns were0.0024%)

Updated performance information is available (1) by contacting your Financial Advisor, (2) by calling1-888-793 8637 (Option #1) and (3) on the fund’s website at https://www.ubs.com/usmoneymarketfunds.

Average annual total returns (for the periods ended December 31, 2019)

One year 1.97%

Five years 0.90

Ten years 0.45

Investment advisorUBS AM serves as the investment advisor to the fund.

Purchase & sale of fund sharesIf you are buying or selling fund shares directly, you may do so by calling the fund’s transfer agent at1-888-547 FUND. You may also buy and sell fund shares through financial intermediaries who are authorizedto accept purchase and sales orders on behalf of the fund. The minimum investment level for initial purchasesgenerally is $1,000. Shares of the fund may be redeemed in the same manner as they were purchased (i.e.,directly or through a financial intermediary). Shares can be purchased and redeemed on any business day onwhich the Federal Reserve Bank of New York, the New York Stock Exchange and the principal bond markets(as recommended by the Securities Industry and Financial Markets Association) are open (unless a liquidity feeand/or temporary redemption gate has been imposed under exceptional circumstances).

7

Tax informationThe dividends and distributions you receive from the fund are taxable and will generally be taxed as ordi-nary income, capital gains or some combination of both, unless you hold shares through a tax-exemptaccount or plan, such as an individual retirement account or 401(k) plan, in which case dividends and dis-tributions on your shares generally will be taxed when withdrawn from the tax-exempt account or plan.

Payments to broker-dealers and other financial intermediariesIf you purchase the fund through a broker-dealer or other financial intermediary (such as a bank), UBS AMand/or its affiliates may pay the intermediary for the sale of fund shares and related services, or othershareholder services. These payments may create a conflict of interest by influencing the broker-dealer orother intermediary and your financial advisor to recommend the fund over another investment. Ask yourfinancial advisor or visit your financial intermediary’s website for more information.

8

UBS Select Government Investor FundFund summary









Other expenses 0.13






* The fund invests in securities through an underlying master fund, Government Master Fund. This table reflects the direct expenses of the fund and its shareof expenses of Government Master Fund, including management fees allocated from Government Master Fund. Management fees are comprised of invest-ment advisory and administration fees.

1 The fund and UBS Asset Management (Americas) Inc. (“UBS AM”) have entered into a written fee waiver/expense reimbursement agreement pursuant towhich UBS AM is contractually obligated to waive its management fees and/or reimburse the fund so that the fund’s operating expenses throughAugust 31, 2021 (excluding interest expense, if any, and extraordinary items) would not exceed 0.50%. The fund has agreed to repay UBS AM for anywaived fees/reimbursed expenses to the extent that it can do so over the three years following such waived fees/reimbursed expenses without causing thefund’s expenses in any of those three years to exceed the expense cap in place at the time the fee was waived. The fee waiver/expense reimbursementagreement may be terminated by the fund’s board at any time and also will terminate automatically upon the expiration or termination of the fund’s con-tract with UBS AM. Upon termination of the agreement, however, UBS AM’s three year recoupment rights will survive.

9




UBS Select Government Investor Fund $51 $178 $316 $718


Principal strategiesPrincipal investmentsThe fund is a money market fund and seeks to maintain a stable price of $1.00 per share. To do this, thefund invests in a diversified portfolio of high quality, US government money market instruments and inrelated repurchase agreements.

Money market instruments generally are short-term debt obligations and similar securities. They also mayinclude longer-term bonds that have variable interest rates or other special features that give them thefinancial characteristics of short-term debt. The fund has adopted a policy to invest 99.5% or more of itstotal assets in cash, government securities, and/or repurchase agreements that are collateralized fully (i.e.,collateralized by cash and/or government securities) in order to qualify as a “government money marketfund” under federal regulations. By operating as a government money market fund, the fund is exemptfrom requirements that permit the imposition of a liquidity fee and/or temporary redemption gates. Whilethe fund’s board may elect to subject the fund to liquidity fee and gate requirements in the future, theboard has not elected to do so at this time. Many US government money market instruments pay incomethat is generally exempt from state and local income tax, although they may be subject to corporate fran-chise tax in some states. The fund generally seeks to invest in securities the income from which is consid-ered “qualified interest income” under relevant tax law and guidance. In addition, under normalcircumstances, the fund invests at least 80% of its net assets in US government securities, including gov-ernment securities subject to repurchase agreements.

The fund may invest a significant percentage of its assets in repurchase agreements. Repurchase agree-ments are transactions in which the fund purchases government securities and simultaneously commits toresell them to the same counterparty at a future time and at a price reflecting a market rate of interest.Income from repurchase agreements may not be exempt from state and local income taxation. Repur-chase agreements often offer a higher yield than investments directly in government securities. In decidingwhether an investment in a repurchase agreement is more attractive than a direct investment in govern-ment securities, the fund considers the possible loss of this tax advantage.


10




You could lose money by investing in the fund. Although the fund seeks to preserve the value of yourinvestment at $1.00 per share, it cannot guarantee it will do so. An investment in the fund is not insuredor guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The fund’ssponsor has no legal obligation to provide financial support to the fund, and you should not expect thatthe sponsor will provide financial support to the fund at any time.





Market risk: The risk that the market value of the fund’s investments may fluctuate, sometimes rapidly orunpredictably, as the markets fluctuate, which may affect the fund’s share price. Market risk may affect asingle issuer, industry, or sector of the economy, or it may affect the market as a whole. Moreover,

11

changing market, economic, political and social conditions in one country or geographic region couldadversely impact market, economic, political and social conditions in other countries or regions.



US withholding tax risk: The fund generally seeks to invest in securities the income from which is con-sidered “qualified interest income” under relevant tax law and guidance. Thus, the fund generally expectsits distributions to be exempt from US withholding tax when paid to non-US investors. However, there canbe no assurance that all of the fund’s distributions will be exempt from US withholding tax.



The table that follows the bar chart shows the average annual returns over various time periods for thefund’s shares.


UBS Select Government Investor Fund Annual Total ReturnTotal return (2017 was the fund’s first full calendar year of operations)

0

1

2

3%

2019Calendar Year

2017

0.46%

2018

1.42%1.80%

Total return January 1 to June 30, 2020: 0.25%Best quarter during years shown—2Q 2019: 0.50%Worst quarter during years shown—1Q 2017: 0.04%

12


Average annual total returns (for the periods ended December 31, 2019)One year 1.80%

Life of fund (inception date August 17, 2016) 1.09


Purchase & sale of fund sharesIf you are buying or selling fund shares directly, you may do so by calling the fund’s transfer agent at1-888-547 FUND. You may also buy and sell fund shares through financial intermediaries who are autho-rized to accept purchase and sales orders on behalf of the fund. The minimum investment level for initialpurchases generally is $1,000. Subsequent purchases, and purchases through exchanges, may be subjectto a minimum investment level of $1,000. Shares of the fund may be redeemed in the same manner asthey were purchased (i.e., directly or through a financial intermediary). Shares can be purchased andredeemed on any business day on which the Federal Reserve Bank of New York, the New York StockExchange and the principal bond markets (as recommended by the Securities Industry and Financial Mar-kets Association) are open.



13

UBS Select Treasury Investor FundFund summary









Other expenses 0.12






* The fund invests in securities through an underlying master fund, Treasury Master Fund. This table reflects the direct expenses of the fund and its share ofexpenses of Treasury Master Fund, including management fees allocated from Treasury Master Fund. Management fees are comprised of investment advi-sory and administration fees.


14




UBS Select Treasury Investor Fund $51 $176 $311 $707


Principal strategiesPrincipal investmentsThe fund is a money market fund and seeks to maintain a stable price of $1.00 per share. To do this,under normal circumstances, the fund invests in a diversified portfolio of high quality, US Treasury moneymarket instruments and in related repurchase agreements.

Money market instruments generally are short-term debt obligations and similar securities. They also mayinclude longer-term bonds that have variable interest rates or other special features that give them thefinancial characteristics of short-term debt. The fund has adopted a policy to invest 99.5% or more of itstotal assets in cash, government securities, and/or repurchase agreements that are collateralized fully (i.e.,collateralized by cash and/or government securities) in order to qualify as a “government money marketfund” under federal regulations. By operating as a government money market fund, the fund is exemptfrom requirements that permit the imposition of a liquidity fee and/or temporary redemption gates. Whilethe fund’s board may elect to subject the fund to liquidity fee and gate requirements in the future, theboard has not elected to do so at this time. In addition, in order to be a “Treasury” fund, under normalcircumstances, the fund seeks to achieve its objective by investing at least 80% of its net assets (plus theamount of any borrowing for investment purposes) in securities issued by the US Treasury and in relatedrepurchase agreements. For purposes of this policy, repurchase agreements are those that are collateral-ized fully by securities issued by the US Treasury and cash. Under normal circumstances, the fund expectsto invest substantially all of its assets in securities issued by the US Treasury and in related repurchaseagreements. Many US government money market instruments pay income that is generally exempt fromstate and local income tax, although they may be subject to corporate franchise tax in some states.

The fund may invest a significant percentage of its assets in repurchase agreements. Repurchase agree-ments are transactions in which the fund purchases securities issued by the US Treasury and simultane-ously commits to resell them to the same counterparty at a future time and at a price reflecting a marketrate of interest. Income from repurchase agreements may not be exempt from state and local incometaxation. Repurchase agreements often offer a higher yield than investments directly in securities issued bythe US Treasury. In deciding whether an investment in a repurchase agreement is more attractive than a

15

direct investment in securities issued by the US Treasury, the fund considers the possible loss of this taxadvantage.

Money market instruments generally are short-term debt obligations and similar securities. They also mayinclude longer-term bonds that have variable interest rates or other special features that give them thefinancial characteristics of short-term debt.





You could lose money by investing in the fund. Although the fund seeks to preserve the value of yourinvestment at $1.00 per share, it cannot guarantee it will do so. An investment in the fund is not insuredor guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The fund’ssponsor has no legal obligation to provide financial support to the fund, and you should not expect thatthe sponsor will provide financial support to the fund at any time.




16







The table that follows the bar chart shows the average annual returns over the various time periods for thefund’s shares.


17

UBS Select Treasury Investor Fund Annual Total ReturnsTotal return

Calendar Year

0

1

2

3

4%

2019

0.01%

2010

0.01%

2011

0.01%

2012

0.01%

2013

0.02%

2015 2017 2018

1.42%

0.01%

2014 2016

0.02%0.45%

1.79%

Total return January 1 to June 30, 2020: 0.23%Best quarter during years shown—2Q 2019: 0.49%Worst quarters during years shown—1Q, 2Q & 3Q 2010; 1Q 2011: 0.00% (Actual total returns were0.0024%)


Average annual total returns (for the periods ended December 31, 2019)

One year 1.79%

Five years 0.74

Ten years 0.37


Purchase & sale of fund sharesIf you are buying or selling fund shares directly, you may do so by calling the fund’s transfer agent at1-888-547 FUND. You may also buy and sell fund shares through financial intermediaries who are authorizedto accept purchase and sales orders on behalf of the fund. The minimum investment level for initial pur-chases generally is $1,000. Shares of the fund may be redeemed in the same manner as they were pur-chased (i.e., directly or through a financial intermediary). Shares can be purchased and redeemed on anybusiness day on which the Federal Reserve Bank of New York, the New York Stock Exchange and the princi-pal bond markets (as recommended by the Securities Industry and Financial Markets Association) are open.

18



19

UBS Select ESG Prime Investor FundFund summary

Investment objectiveMaximum current income as is consistent with liquidity and preservation of capital while incorporatingselect environmental, social, and governance criteria (“ESG”) into the investment process.








Other expenses 3.13






* The fund invests in securities through an underlying master fund, ESG Prime Master Fund. This table reflects the direct expenses of the fund and its shareof expenses of ESG Prime Master Fund, including management fees allocated from ESG Prime Master Fund. Management fees are comprised of invest-ment advisory and administration fees.


20




UBS Select ESG Prime Investor Fund $51 $810 $1,591 $3,641


Principal strategiesPrincipal investmentsThe fund is a money market fund that calculates its net asset value to four decimals (e.g., $1.0000) usingmarket-based pricing. As a result, its share price will fluctuate. The fund seeks to achieve its objective byinvesting in a diversified portfolio of high quality money market instruments of governmental and privateissuers while incorporating fundamental sustainability factors, such as ESG performance of such issuers,into the investment process. Money market instruments may include:

• short-term obligations of the US government and its agencies and instrumentalities;• repurchase agreements;• obligations of issuers in the financial services group of industries;• commercial paper, other corporate obligations and asset-backed securities; and• municipal money market instruments.

Money market instruments generally are short-term debt obligations and similar securities. They also mayinclude longer-term bonds that have variable interest rates or other special features that give them thefinancial characteristics of short-term debt. The fund invests in foreign money market instruments only ifthey are denominated in US dollars. The fund will, under normal circumstances, invest more than 25% ofits total assets in the financial services group of industries.

In addition, under normal circumstances, the fund invests at least 80% of its net assets (plus the amountof any borrowing for investment purposes), determined at the time of purchase, in securities that meetUBS AM’s sustainability criteria. In developing its sustainability criteria, UBS AM draws upon firm-wideresources of the UBS Asset Management Division of UBS Group AG, of which UBS AM is a member.

UBS AM conducts its own credit analyses of potential investments and portfolio holdings, and relies sub-stantially on a dedicated proprietary credit research team. Embedded in the credit research process is theintegration of issuer-level sustainability investing analysis as guided by the UBS Asset Management Divi-sion’s approach to ESG research and evaluation methodology. The sustainability investing analysis providesa more comprehensive approach to security selection than credit analysis alone as internal and external ESG

21

ratings are applied to evaluate the quality of sustainability practices employed by issuers. Analysts rate andmaintain internal fundamental credit and ESG ratings, which form the basis for a portfolio construction/optimization approach and focus on issuers that contribute to the fund’s ESG profile. In determining anissuer’s ESG ratings, analysts will evaluate whether, at the time of the fund’s investment, such issuers havebetter than average performance in ESG practices and managing ESG risks by reviewing, among otherfactors, such considerations as the issuer’s environmental responsibility, human rights and labor standards,diversity and inclusion in employment and corporate governance based on proprietary and third-party data.UBS AM also will employ a negative screening process with regard to security selection, which will excludefrom the fund’s portfolio securities or sectors that manufacture products or engage in business activitiesviewed as having a negative social or environmental impact. UBS AM’s portfolio construction process aimsto align investments in money market instruments with the concept of sustainability (i.e., the potential forlong-term maintenance of environmental, economic and social well-being).


The fund may be subject to the possible imposition of a liquidity fee and/or temporary redemption gateshould certain triggering events occur.



UBS AM is part of the UBS Asset Management Division of UBS Group AG. The UBS Asset ManagementDivision, at the global level, seeks to be a leader in incorporating sustainability into its management pro-cess and honors various commitments in the sustainability investing industry. Active commitments include:

• Participant in the UN Global Compact since its inception in 2000• Independent assurance of the GRI (Global Reporting Initiative) based sustainability disclosure• UBS Asset Management signatory to Principles for Responsible Investment (PRI)• Global Initiative for Sustainability Ratings steering committee• Sustainability Accounting Standards BoardTM• The Forum for Sustainable and Responsible Investing


22

You could lose money by investing in the fund. Because the share price of the fund will fluctuate, whenyou sell your shares they may be worth more or less than what you originally paid for them. Also, the fundmay impose a fee upon the sale of your shares or may temporarily suspend your ability to sell shares if thefund’s liquidity falls below required minimums because of market conditions or other factors. An invest-ment in the fund is not insured or guaranteed by the Federal Deposit Insurance Corporation or any othergovernment agency. The fund’s sponsor has no legal obligation to provide financial support to the fund,and you should not expect that the sponsor will provide financial support to the fund at any time.




Sustainability factor risk: Investing primarily in investments that meet ESG criteria carries the risk thatthe fund may forgo otherwise attractive investment opportunities, or increase or decrease its exposure tocertain types of issuers and, therefore, may underperform compared to funds that do not consider ESGfactors in the investment process.




Concentration risk: The fund will invest a significant portion of its assets in securities issued by compa-nies in the financial services group of industries, including US banking, non-US banking, broker-dealers,insurance companies, finance companies (e.g., automobile finance) and related asset-backed securities.

23

Accordingly, the fund will be more susceptible to developments that affect those industries than otherfunds that do not concentrate their investments.

Financial services sector risk: Investments of the fund in the financial services sector may be particularlyaffected by economic cycles, business developments, interest rate changes and regulatory changes.

US Government securities risk: There are different types of US government securities with different lev-els of credit risk, including the risk of default, depending on the nature of the particular government sup-port for that security. For example, a US government-sponsored entity, such as Federal National MortgageAssociation (“Fannie Mae”) or Federal Home Loan Mortgage Corporation (“Freddie Mac”), althoughchartered or sponsored by an Act of Congress, may issue securities that are neither insured nor guaran-teed by the US Treasury and are therefore riskier than those that are.

Foreign investing risk: The value of the fund’s investments in foreign securities may fall due to adversepolitical, social and economic developments abroad. However, because the fund’s foreign investmentsmust be denominated in US dollars, it generally is not subject to the risk of changes in currency valuations.

Municipal securities risk: Municipal securities are subject to interest rate and credit risks. The ability of amunicipal issuer to make payments and the value of municipal securities can be affected by uncertaintiesin the municipal securities market. Such uncertainties could cause increased volatility in the municipal secu-rities market and could negatively impact the fund’s net asset value and/or the distributions paid by thefund. Municipalities continue to experience difficulties in the current economic and political environment.

New fund risk: The fund is new with a limited operating history. As a result, prospective investors have alimited track record or history on which to base their investment decisions.

PerformanceThere is no performance information quoted for the fund as the fund has not yet operated for a full calen-dar year as of the date of this prospectus.


Purchase & sale of fund sharesIf you are buying or selling fund shares directly, you may do so by calling the fund’s transfer agent at1-888-547 FUND. You may also buy and sell fund shares through financial intermediaries who are authorizedto accept purchase and sales orders on behalf of the fund. The minimum investment level for initial purchasesgenerally is $1,000. Shares of the fund may be redeemed in the same manner as they were purchased (i.e.,directly or through a financial intermediary). Shares can be purchased and redeemed on any business day onwhich the Federal Reserve Bank of New York, the New York Stock Exchange and the principal bond markets(as recommended by the Securities Industry and Financial Markets Association) are open (unless a liquidity feeand/or temporary redemption gate has been imposed under exceptional circumstances).

24



25

UBS Series Funds

More information about the funds

Additional information about the investmentobjectivesEach of UBS Select Prime Investor Fund’s, UBSSelect Government Investor Fund’s and UBS SelectTreasury Investor Fund’s investment objective maynot be changed without shareholder approval. Theinvestment objective of UBS Select ESG Prime Inves-tor Fund is non-fundamental and may be changedby the fund’s board at any time without share-holder approval.

Additional information about investmentstrategiesUBS Select Prime Investor Fund seeks to achieve itsinvestment objective by investing in a diversifiedportfolio of high quality money market instrumentsof governmental and private issuers, which mayinclude short-term obligations of the US govern-ment and its instrumentalities; repurchase agree-ments; obligations of issuers in the financial servicesgroup of industries; commercial paper, other corpo-rate obligations and asset-backed securities; andmunicipal money market instruments.

UBS Select Prime Investor Fund calculates its net assetvalue to four decimals (e.g., $1.0000) using market-based pricing, and its share price will fluctuate.

UBS Select Prime Investor Fund will, under normalcircumstances, invest more than 25% of its totalassets in the financial services group of industries.UBS Select Prime Investor Fund may, however,invest less than 25% of its total assets in this groupof industries as a temporary defensive measure.

UBS Select Prime Investor Fund may be subject tothe possible imposition of a liquidity fee and/ortemporary redemption gate should certain trigger-ing events occur.

UBS Select Government Investor Fund seeks toachieve its investment objective by investing in adiversified portfolio of high quality, US governmentmoney market instruments and in related repurchaseagreements, which generally are short-term debtobligations and similar securities. They also mayinclude longer-term bonds that have variable interestrates or other special features that give them thefinancial characteristics of short-term debt. Many USgovernment money market instruments pay incomethat is generally exempt from state and local incometax, although they may be subject to corporate fran-chise tax in some states. The fund generally seeks toinvest in securities the income from which is consid-ered “qualified interest income” under relevant taxlaw and guidance. UBS Select Government InvestorFund may invest a significant percentage of its assetsin repurchase agreements. Repurchase agreementsare transactions in which the fund purchases govern-ment securities and simultaneously commits to resellthem to the same counterparty at a future time andat a price reflecting a market rate of interest. Incomefrom repurchase agreements may not be exemptfrom state and local income taxation. Repurchaseagreements often offer a higher yield than invest-ments directly in government securities. In decidingwhether an investment in a repurchase agreement ismore attractive than a direct investment in govern-ment securities, the fund considers the possible lossof this tax advantage.

UBS Select Government Investor Fund’s board hasdetermined that the fund will operate as a “govern-ment money market fund” pursuant to Rule 2a-7under the Investment Company Act of 1940, asamended (“Rule 2a-7”). Therefore, the fund hasadopted a policy to invest 99.5% or more of its totalassets in cash, government securities, and/or repur-chase agreements that are collateralized fully

26

UBS Series Funds

(i.e., collateralized with cash and/or governmentsecurities). As a “government money market fund,”the fund (1) is permitted to use the amortized costmethod of valuation to seek to maintain a $1.00share price, and (2) is not subject to a liquidity feeand/or a redemption gate on fund redemptionswhich might apply to other types of funds shouldcertain triggering events specified in Rule 2a-7 occur.(In conformance with Rule 2a-7, UBS Select Govern-ment Investor Fund’s board has reserved its ability tochange this policy with respect to liquidity fees and/or redemption gates, but such change would onlybecome effective after shareholders were providedwith specific advance notice of a change in thefund’s policy and have the opportunity to redeemtheir shares in accordance with Rule 2a-7 before thepolicy change became effective.)

In addition, under normal circumstances, UBS SelectGovernment Investor Fund invests at least 80% ofits net assets in US government securities, includinggovernment securities subject to repurchase agree-ments. UBS Select Government Investor Fund’s80% policy is a “non-fundamental” policy. Thismeans that this investment policy may be changedby the fund’s board without shareholder approval.However, UBS Select Government Investor Fund hasalso adopted a policy to provide its shareholderswith at least 60 days’ prior written notice of anychange to the 80% investment policy.

UBS Select Treasury Investor Fund seeks to achieve itsinvestment objective by investing at least 80% of itsnet assets (plus the amount of any borrowing forinvestment purposes) in securities issued by theUS Treasury and in related repurchase agreements.While under normal circumstances UBS Select Trea-sury Investor Fund expects to invest substantially all ofits assets in securities issued by the US Treasury andin related repurchase agreements, under unusual cir-cumstances, the fund may invest a portion of itsassets in other types of government securities.

UBS Select Treasury Investor Fund’s board hasdetermined that the fund will operate as a“government money market fund” underRule 2a-7. Therefore, in addition to the 80% policyreferenced above, the fund has adopted a policy toinvest 99.5% or more of its total assets in cash,government securities, and/or repurchase agree-ments that are collateralized fully (i.e., collateralizedwith cash and/or government securities). As a “gov-ernment money market fund” under Rule 2a-7, thefund (1) is permitted to use the amortized costmethod of valuation to seek to maintain a $1.00share price, and (2) is not subject to a liquidity feeand/or a redemption gate on fund redemptionswhich might apply to other types of funds shouldcertain triggering events specified in Rule 2a-7occur. (In conformance with Rule 2a-7, UBS SelectTreasury Investor Fund’s board has reserved its abil-ity to change this policy with respect to liquidityfees and/or redemption gates, but such changewould only become effective after shareholderswere provided with specific advance notice of achange in the fund’s policy and have the opportu-nity to redeem their shares in accordance with Rule2a-7 before the policy change became effective.)

UBS Select Treasury Investor Fund’s 80% policy is a“non-fundamental” policy. This means that thisinvestment policy may be changed by the fund’sboard without shareholder approval. However, UBSSelect Treasury Investor Fund has also adopted apolicy to provide its shareholders with at least 60days’ prior written notice of any change to the80% investment policy.

UBS Select ESG Prime Investor Fund seeks toachieve its investment objective by investing in adiversified portfolio of high quality money marketinstruments of governmental and private issuerswhile incorporating fundamental sustainability fac-tors, such as ESG performance of such issuers, into

27

UBS Series Funds

the investment process. Money market instrumentsmay include short-term obligations of the US gov-ernment and its instrumentalities; repurchaseagreements; obligations of issuers in the financialservices group of industries; commercial paper,other corporate obligations and asset-backed secu-rities; and municipal money market instruments.

UBS Select ESG Prime Investor Fund calculates itsnet asset value to four decimals (e.g., $1.0000)using market based pricing, and its share price willfluctuate.

Under normal circumstances, UBS Select ESG PrimeInvestor Fund invests at least 80% of its net assets(plus the amount of any borrowing for investmentpurposes), determined at the time of purchase, insecurities that meet UBS AM’s sustainability criteria.In developing its sustainability criteria, UBS AMdraws upon firm-wide resources of the UBS AssetManagement Division of UBS Group AG, of whichUBS AM is a member. UBS Select ESG Prime Inves-tor Fund’s 80% policy is a “non-fundamental” pol-icy. This means that this investment policy may bechanged by the fund’s board without shareholderapproval. However, UBS Select ESG Prime InvestorFund has also adopted a policy to provide its share-holders with at least 60 days’ prior written notice ofany change to the 80% investment policy.

UBS Select ESG Prime Investor Fund will, under nor-mal circumstances, invest more than 25% of itstotal assets in the financial services group of indus-tries. UBS Select ESG Prime Investor Fund may,however, invest less than 25% of its total assets inthis group of industries as a temporary defensivemeasure.

UBS AM conducts its own credit analyses of poten-tial investments and portfolio holdings, and reliessubstantially on a dedicated proprietary credit

research team. Embedded in the credit research pro-cess is the integration of issuer-level sustainabilityinvesting analysis as guided by the UBS Asset Man-agement Division’s approach to ESG research andevaluation methodology. The sustainability investinganalysis provides a more comprehensive approachto security selection than credit analysis alone asinternal and external ESG ratings are applied to eval-uate the quality of sustainability practices employedby issuers. Analysts rate and maintain internal fun-damental credit and ESG ratings which form thebasis of a portfolio construction/optimizationapproach, focusing on companies that contribute tomeeting the ESG profile for the fund. Portfolio con-struction focuses on the alignment of a Rule 2a-7(the regulation governing money market funds)investment discipline with the concept of sustain-ability—the potential for long-term maintenance ofenvironmental, economic and social well-being.

Sustainability criteria includes the fundamentalanalysis of ESG risks of issuers (that is, the issuers ofthe money market instruments in which the fundmay invest), and evaluating whether, at the time ofthe fund’s investment, such issuers have better thanaverage performance in ESG practices and manag-ing ESG risks. The fundamental analysis of ESG risksmay include, but is not limited to, review of the fol-lowing factors:

• environmental responsibility• human rights and labor standards• diversity and inclusion in employment• corporate governance

UBS AM will employ a negative screening processwith regard to security selection for UBS Select ESGPrime Investor Fund, which will exclude from thefund’s portfolio securities or sectors that manufac-ture products or engage in business activities

28

UBS Series Funds

viewed as having a negative social or environmentalimpact. These may include:

• controversial weapons• antipersonnel mines• cluster munitions• adult entertainment (5% revenue threshold)• tobacco producers (5% revenue threshold)• thermal coal (30% revenue threshold)• generation thermal coal (30% revenue threshold)

UBS AM may modify this list of negative screens atany time, without prior shareholder approval ornotice.

UBS Select ESG Prime Investor Fund may be subjectto the possible imposition of a liquidity fee and/ortemporary redemption gate should certain trigger-ing events occur.

UBS AM serves as investment advisor to a range ofmoney market funds following different investmentfocuses/strategies. These include other “prime”money market funds (including UBS Select PrimeInvestor Fund), which may invest in similar types ofsecurities as UBS Select ESG Prime Investor Fund.There may be overlap between the portfolio holdingsand investments of UBS Select ESG Prime InvestorFund and other “prime” money market funds forwhich UBS AM serves as investment advisor.

Like all money market funds, each of the funds issubject to maturity, quality, diversification andliquidity requirements pursuant to Rule 2a-7. Eachof the funds’ investment strategies are designed tocomply with these requirements. Each of the fundsmay invest in high quality, short-term, US dollar-denominated money market instruments paying afixed, variable or floating interest rate.

UBS AM may use a number of professional moneymanagement techniques to respond to changingeconomic and money market conditions and toshifts in fiscal and monetary policy. These tech-niques include varying each fund’s composition andweighted average maturity based upon UBS AM’sassessment of the relative values of various moneymarket instruments and future interest ratepatterns. UBS AM also may buy or sell money mar-ket instruments to take advantage of yielddifferences.

Each of the master funds in which the funds investmay maintain a rating from one or more ratingagencies that provide ratings on money marketfunds. There can be no assurance that a masterfund will maintain any particular rating or maintainit with a particular rating agency. To maintain a rat-ing, UBS AM may manage a corresponding masterfund more conservatively or differently than if itwere not rated.

Additional information about principal risksThe main risks of investing in the funds aredescribed below. As indicated below, not all ofthese risks apply to each fund. The fund(s) to whichthe main risks apply are noted below.

Other risks of investing in a fund, along with fur-ther details about some of the risks describedbelow, are discussed in the funds’ Statement ofAdditional Information (“SAI”). Information on howyou can obtain the SAI can be found on the backcover of this prospectus.

Credit risk (All funds). Credit risk is the risk thatthe issuer of money market instruments or financialinstitutions that have entered into repurchaseagreements with a fund will not make principal orinterest payments when they are due or completetransactions. Even if an issuer or counterparty does

29

UBS Series Funds

not default on a payment, a money market instru-ment’s value may decline if the market believes thatthe issuer or counterparty has become less able, orless willing, to make payments on time. Even thehighest quality money market instruments are sub-ject to some credit risk. The credit quality of anissuer or counterparty can change rapidly due tomarket developments and may affect the fund’sshare price.

Interest rate risk (All funds). The value of moneymarket instruments generally can be expected tofall when short-term interest rates rise and to risewhen short-term interest rates fall. Interest rate riskis the risk that interest rates will rise, so that thevalue of a fund’s investments will fall. Also, a fund’syield will tend to lag behind changes in prevailingshort-term interest rates. This means that a fund’sincome will tend to rise more slowly than increasesin short-term interest rates. Similarly, when short-term interest rates are falling, a fund’s income gen-erally will tend to fall more slowly.

A fund may face a heightened level of interest raterisk due to certain changes in monetary policy, suchas certain types of interest rate changes by theFederal Reserve. The risks associated with changinginterest rates may have unpredictable effects on themarkets and a fund’s investments. A sudden orunpredictable increase in interest rates may causevolatility in the market and may decrease liquidity inthe money market securities markets, making itharder for a fund to sell its money market invest-ments at an advantageous time. Decreased marketliquidity also may make it more difficult to valuesome or all of a fund’s money market securitiesholdings. Certain countries have experienced nega-tive interest rates on certain fixed-income securities.A low or negative interest rate environment maypose additional risks to a fund because low or neg-ative yields on a fund’s portfolio holdings may have

an adverse impact on a fund’s ability to provide apositive yield to its shareholders, pay expenses outof fund assets, or minimize the volatility of a fund’sNAV per share.

Sustainability factor risk (UBS Select ESG PrimeInvestor Fund). Investing primarily in investmentsthat meet ESG criteria carries the risk that UBSSelect ESG Prime Investor Fund may forgo other-wise attractive investment opportunities, or increaseor decrease its exposure to certain types of issuersand, therefore, may underperform compared tofunds that do not consider ESG factors in theinvestment process. UBS AM’s assessment of anissuer’s ESG criteria may change over time, whichcould cause the fund to hold securities that may nolonger meet UBS AM’s current ESG criteria.

Investing on the basis of ESG criteria is qualitativeand subjective by nature and there can be no assur-ance that the process utilized by any vendors ofUBS AM or any judgment exercised by UBS AM willreflect the beliefs or values of any particular inves-tor. In addition, due to constraints imposed by reg-ulations applicable to money market funds or otherconsiderations relating to credit quality, liquidity oryield, the fund may be less able to implement asfully its ESG investment strategy than non-moneymarket funds.

Market risk (All funds). The risk that the marketvalue of a fund’s investments will fluctuate as thestock and fixed-income markets fluctuate. Marketrisk may affect a single issuer, industry or sector ofthe economy, or it may affect the market as awhole. In addition, turbulence in financial marketsand reduced liquidity in equity and/or fixed-incomemarkets may negatively affect a fund. Globaleconomies and financial markets are becomingincreasingly interconnected, and conditions andevents in one country, region or financial market

30

UBS Series Funds

may adversely impact issuers in a different country,region or financial market. These risks may be mag-nified if certain events or developments adverselyinterrupt the global supply chain, and could affectcompanies worldwide. Recent examples includepandemic risks related to the novel coronavirus(“COVID-19”) and the aggressive measures takenworldwide in response by (i) governments, includ-ing closing borders, restricting travel and imposingprolonged quarantines of, or similar restrictions on,large populations, and (ii) businesses, includingforced or voluntary closures, changes to operationsand reductions of staff. The effects of COVID-19have contributed to increased volatility in globalfinancial markets and may affect certain countries,regions, companies, industries and market sectorsmore dramatically than others. The COVID-19 pan-demic has had, and any other outbreak of an infec-tious disease or serious environmental or publichealth concern could have, a significant negativeimpact on economic and market conditions, couldexacerbate pre-existing political, social and eco-nomic risks in certain countries or regions and couldtrigger a prolonged period of global economicslowdown, which may impact a fund. It is notknown how long the impact of the COVID-19 pan-demic will, or future impacts of other significantevents would, last or the severity thereof. To theextent a fund is overweight in certain countries,regions, companies, industries or market sectors,such positions will increase the risk of loss fromadverse developments affecting those countries,regions, companies, industries or sectors.

Liquidity risk (All funds). The funds’ investmentsmay become less liquid due to market develop-ments or adverse investor perception. When thereis no willing buyer and investments cannot be read-ily sold at the desired time or price, the funds mayhave to accept a lower price or may not be able tosell an instrument at all. The inability to sell an

instrument could adversely affect a fund’s shareprice or prevent the fund from being able to takeadvantage of other investment opportunities. Thisrisk may increase during an unusually high volumeof redemption requests by even a few large inves-tors or unusual market conditions.

Management risk (All funds). There is the riskthat the investment strategies, techniques and riskanalyses employed by the advisor may not producethe desired results. The advisor may be incorrect inits assessment of a particular security or assessmentof market, interest rate or other trends, which canresult in losses to a fund.

Concentration risk (UBS Select Prime InvestorFund and UBS Select ESG Prime Investor Fund).Each of UBS Select Prime Investor Fund and UBSSelect ESG Prime Investor Fund will invest a signifi-cant portion of its assets in securities issued bycompanies in the financial services group of indus-tries, including US banking, non-US banking,broker-dealers, insurance companies, finance com-panies (e.g., automobile finance) and related asset-backed securities. As a result, each fund’sperformance will be significantly impacted, bothpositively and negatively, by developments in thefinancial services sector, and each fund will be moresusceptible to such developments than other fundsthat do not concentrate their investments.

Financial services sector risk (UBS Select PrimeInvestor Fund and UBS Select ESG Prime Inves-tor Fund). Investments of UBS Select Prime InvestorFund and UBS Select ESG Prime Investor Fund in thefinancial services sector may be particularly affectedby economic cycles, business developments, interestrate changes and regulatory changes. For example,declining economic and business conditions can dis-proportionately impact companies in the financialservices sector due to increased defaults on

31

UBS Series Funds

payments by borrowers. Interest rate increases canalso adversely affect the financial services sector byincreasing the cost of capital available for financialservices companies. In addition, financial servicescompanies are heavily regulated by governmentalentities and, as a result, political and regulatorychanges can affect the operations and financialresults of such companies, potentially imposingadditional costs and possibly restricting the busi-nesses in which those companies may engage.

US Government securities risk (All funds).Credit risk is the risk that the issuer will not makeprincipal or interest payments when they are due.There are different types of US government securi-ties with different relative levels of credit riskdepending on the nature of the particular govern-ment support for that security. US governmentsecurities may be supported by (1) the full faith andcredit of the US; (2) the ability of the issuer to bor-row from the US Treasury; (3) the credit of the issu-ing agency, instrumentality or government-sponsored entity; (4) pools of assets (e.g.,mortgage-backed securities); or (5) the US in someother way. In some cases, there is even the risk ofdefault. For example, for asset-backed securitiesthere is the risk those assets will decrease in valuebelow the face value of the security. Similarly, forcertain agency issued securities there is no guaran-tee the US government will support the agency if itis unable to meet its obligations. Further, the USgovernment and its agencies and instrumentalitiesdo not guarantee the market value of their securi-ties; consequently, the value of such securities willfluctuate. This may be the case especially whenthere is any controversy or ongoing uncertaintyregarding the status of negotiations in the USCongress to increase the statutory debt ceiling. Ifthe US Congress is unable to negotiate an adjust-ment to the statutory debt ceiling, there is also therisk that the US government may default on

payments on certain US government securities,including those held by the funds, which couldhave a material negative impact on the funds.

Foreign investing risk (UBS Select Prime Inves-tor Fund and UBS Select ESG Prime InvestorFund). UBS Select Prime Investor Fund and UBSSelect ESG Prime Investor Fund may invest in for-eign money market instruments that are denomi-nated in US dollars. Foreign investing may involverisks relating to political, social and economic devel-opments abroad to a greater extent than investingin the securities of US issuers. In addition, there aredifferences between US and foreign regulatoryrequirements and market practices.

Municipal securities risk (UBS Select PrimeInvestor Fund and UBS Select ESG PrimeInvestor Fund). Municipal securities are subject tointerest rate, credit, illiquidity, market and politicalrisks. The ability of a municipal issuer to make pay-ments and the value of municipal securities can beaffected by uncertainties in the municipal securitiesmarket, including litigation, the strength of the localor national economy, the issuer’s ability to raise reve-nues through tax or other means, the bankruptcy ofthe issuer affecting the rights of municipal securitiesholders and budgetary constraints of local, state andfederal governments upon which the issuer may berelying for funding. Municipal securities and issuersof municipal securities may be more susceptible todowngrade, default and bankruptcy during periodsof economic stress. In addition, the municipal securi-ties market can be significantly affected by politicalchanges, including legislation or proposals at eitherthe state or the federal level to eliminate or limit the

Date post:	31-Jan-2021
Category:	Documents
Upload:	others
View:	1 times
Download:	0 times

UBS Series Funds...UBS Series Funds November 25, 2020 Supplement to the Prospectus dated August 28,...

Documents