Contents

The UBS Funds

What every investor should know about the fund

Fund summaries	Page
• UBS Multi Income Bond Fund		3
• UBS U.S. Small Cap Growth Fund		9
More information about the funds
• UBS Multi Income Bond Fund—Investment objective, strategies, securities selection and risks		13
• UBS U.S. Small Cap Growth Fund—Investment objective, strategies, securities selection and risks		20
Your investment
Information for managing your fund account
• Flexible pricing		24
• Buying shares		24
• Market timers		24
• Selling shares		25
• Exchanging shares		26
• Pricing and valuation		26
Additional information
Additional important information about the fund
• Management		28
• Disclosure of portfolio holdings		31
• Dividends and taxes		31
• Financial highlights		35
• Where to learn more about the fund		Back Cover

Please find the UBS family of funds privacy notice on page 38 of this prospectus.

Please find the UBS Asset Management business continuity planning overview on page 39 of this prospectus.

Investment objective

The Fund seeks to maximize total return, consisting of capital appreciation and current income.

Fees and expenses

These tables describe the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. Shares of Class P2 are available for purchase on behalf of clients of a fee-based program or certain other advisory programs in which UBS Asset Management (Americas) Inc., the Fund's investment advisor and administrator ("UBS AM (Americas)" or the "Advisor"), exercises investment discretion. Clients pay a wrap fee or a similar advisory fee to participate in such programs. Shares of Class P2 are also available for purchase on behalf of institutional clients with which the Advisor or its affiliates have signed a separate investment management agreement, pursuant to which such clients pay an advisory fee.

Shareholder fees (fees paid directly from your investment)

	Class P2
Maximum front-end sales charge (load) imposed on purchases (as a % of offering price)		None
Maximum contingent deferred sales charge (load) (CDSC) (as a % of purchase or sales price, whichever is less)		None

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

	Class P2
Management fees		0.50	%
Distribution and/or service (12b-1) fees		None
Other expenses¹		1.02
Acquired fund fees and expenses²		0.01
Total annual fund operating expenses		1.53
Less management fee waiver/expense reimbursements³		1.32
Total annual fund operating expenses after management fee waiver/expense reimbursements^2,3		0.21

¹ "Other expenses" are based on estimates for the current fiscal year.

²Since the "Acquired fund fees and expenses" are not directly borne by the Fund, they are not reflected in the Fund's financial statements, and therefore the

amounts listed in "Total annual fund operating expenses" will differ from those presented in the Financial highlights.

³ The Trust, with respect to the Fund, and the Advisor have entered into a written agreement pursuant to which the Advisor has agreed to waive its management fees and retained administration fees, and to reimburse expenses (excluding expenses incurred through investment in other investment companies, interest, taxes, brokerage commissions, dividend expense and security loan fees for securities sold short, and extraordinary expenses, such as proxy-related expenses) to the extent necessary so that the Fund's ordinary operating expenses (excluding expenses incurred through investment in other investment companies, interest, taxes, brokerage commissions, dividend expense and security loan fees for securities sold short, and extraordinary expenses, such as proxy-related expenses) through the period ending October 28, 2022 do not exceed 0.20%. Pursuant to the expense limitation agreement, the Advisor is entitled to be reimbursed for any expenses it reimburses to the extent such reimbursement can be made during the three years following the period during which such expense reimbursements were made, provided that the reimbursement of the Advisor by the Fund will not cause the Fund to exceed the lesser of any applicable expense limit that is in place for the Fund (i) at the time of the reimbursement or (ii) at the time of the recoupment. The expense limitation agreement may be terminated by the Fund's Board of Trustees at any time and also will terminate automatically upon the expiration or termination of the Fund's advisory contract with the Advisor. Upon termination of the expense limitation agreement, however, the Advisor's three year recoupment rights will survive.

Example

This example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then sell all of your shares at the end of those periods unless otherwise stated. The example also assumes that your investment has a 5% return each year and that the Fund's operating expenses remain the same. The costs described in the example reflect the expenses of the Fund that would result from the contractual fee waiver and expense reimbursement agreement with the Advisor for the first year only. 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
Class P2				$	22			$	353			$	709			$	1,711

Portfolio turnover

The Fund pays transaction costs, such as mark-ups, when it buys and sells securities (or "turns over" its portfolio). A higher portfolio turnover rate may indicate

higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 169% of the average value of its portfolio.

Principal strategies

Principal investments

Under normal circumstances, the Fund invests at least 80% of its net assets (plus borrowings for investment purposes, if any) in bonds and/or instruments that provide exposure to bond markets.

For purposes of the Fund's 80% policy above, the Fund's investments in bonds include a variety of fixed income securities, which may include, but are not limited to, securities of the US government, its agencies and government-sponsored enterprises, securities guaranteed by the US government, securities issued by municipalities, corporate debt securities of US and non-US issuers, including convertible securities, obligations of non-US governments or their subdivisions, agencies and government-sponsored enterprises, obligations of international agencies or supranational entities, mortgage-backed (including commercial and residential mortgage-backed securities) and asset-backed securities, and other securitized and structured securities. The Fund may also invest in equity securities. Equity investments may include securities of companies of any capitalization size, however the Fund expects to invest primarily in large and mid-capitalization companies.

Under normal circumstances, the Fund will invest at least 50% of its net assets in securities that, at the time of purchase, are rated investment grade by an independent rating agency (or, if unrated, are deemed to be of comparable quality by the Advisor), but may invest up to 50% in securities rated below investment grade (also known as lower-rated or "junk bonds").

The Fund's investments in fixed income securities may have all types of interest rate payment and reset terms, including fixed rate, adjustable rate, and auction rate features. In addition, the fixed income securities purchased by the Fund may be denominated in any currency, have coupons payable in any currency and may be of any maturity or duration.

The Fund invests in the United States and abroad, including in China and other emerging markets, and may purchase securities issued by domestic and foreign issuers. However, the Fund expects to limit foreign currency exposure to 25% of its net assets. Furthermore, no more than 50% of the Fund's net assets may be invested in emerging markets securities. Depending on its assessment of market conditions, the Advisor may choose to allocate the Fund's assets in any combination

among these types of investments or may choose not to invest in these types of investments.

The Fund may, but is not required to, use exchange-traded or over-the-counter ("OTC") derivative instruments for risk management purposes or as part of the Fund's investment strategies. Generally, derivatives are financial contracts whose value depends upon, or is derived from, the value of an underlying asset, reference rate, index or other market factor and may relate to stocks, bonds, interest rates, credit, currencies or currency exchange rates, commodities and related indexes. The derivatives in which the Fund may invest include options (including, options on futures, forwards and swap agreements), futures, forward agreements, swap agreements (including, interest rate, total return, currency, credit default and inflation swaps), credit-linked securities and structured investments. All of these derivatives may be used for risk management purposes, such as hedging against a specific security or currency, or to manage or adjust the risk profile of the Fund. In addition, all of the derivative instruments listed above may be used for investment (non-hedging) purposes to earn income; to enhance returns; to replace more traditional direct investments; to obtain exposure to certain markets; or to establish net short positions for individual sectors, markets, currencies or securities. The Fund may use options, futures, swap agreements, credit-linked securities and structured investments to adjust the Fund's portfolio duration.

The Fund may engage in active and frequent trading of portfolio securities to achieve its principal investment strategies.

Management process

The Advisor's investment strategy is based on identifying compelling and attractive opportunities where the Advisor believes that the return profile sufficiently compensates for the risk of owning a position. The Advisor focuses on identifying relative value opportunities and discrepancies between observable market prices and the Advisor's own estimates of fundamental value across various maturities, sectors and issuers.

Main risks

All investments carry a certain amount of risk, and the Fund cannot guarantee that it will achieve its investment objective. You may lose money by investing in the Fund. An investment in the Fund is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. Below are some of the specific risks of investing in the Fund.

Interest rate risk: An increase in prevailing interest rates typically causes the value of fixed income securities to fall. Changes in interest rates will likely affect the value of longer-duration fixed income securities more than shorter-duration securities and higher quality securities more than lower quality securities. When interest rates are falling, some fixed income securities provide that the issuer may repay them earlier than the maturity date, and if this occurs the Fund may have to reinvest these repayments at lower interest rates. The Fund may face a heightened level of interest rate risk due to certain changes in monetary policy, such as certain types of interest rate changes by the Federal Reserve. During periods when interest rates are low or there are negative interest rates, the Fund's performance may be negatively impacted, and the Fund may experience increased volatility of its net asset value per share. Variable rate securities generally will not increase in market value if interest rates decline. Conversely, the market value may not decline when prevailing interest rates rise. Fixed rate debt securities generally are more sensitive to interest rate changes than variable rate securities.

Credit risk: The risk that the Fund could lose money if the issuer or guarantor of a fixed income security, or the counterparty to or guarantor of a derivative contract, is unable or unwilling to meet its financial obligations. This risk is likely greater for lower quality investments than for investments that are higher quality.

Mortgage- and asset-backed securities risk: The Fund may invest in mortgage- and asset-backed securities that are subject to prepayment or call risk, which is the risk that the borrower's payments may be received earlier or later than expected due to changes in prepayment rates on underlying loans. Faster prepayments often happen when interest rates are falling. As a result, the Fund may reinvest these early payments at lower interest rates, thereby reducing the Fund's income. Conversely, when interest rates rise, prepayments may happen more slowly, causing the security to lengthen in duration. Longer duration securities tend to be more volatile. Securities may be prepaid at a price less than the original purchase value. An unexpectedly high rate of defaults on the mortgages held by a mortgage pool may adversely affect the value of mortgage-backed securities and could result in losses to the Fund.

Liquidity risk: The risk that investments cannot be readily sold at the desired time or price, and the Fund

may have to accept a lower price or may not be able to sell the security at all. An inability to sell securities can adversely affect the Fund's value or prevent the Fund from taking advantage of other investment opportunities. Liquid portfolio investments may become illiquid or less liquid after purchase by the Fund due to low trading volume, adverse investor perceptions and/or other market developments. In recent years, the number and capacity of dealers that make markets in fixed income securities has decreased. Consequently, the decline in dealers engaging in market making trading activities may increase liquidity risk, which can be more pronounced in periods of market turmoil. Liquidity risk may be magnified in a rising interest rate environment or when investor redemptions from fixed income funds may be higher than normal, causing increased supply in the market due to selling activity. Liquidity risk includes the risk that the Fund will experience significant net redemptions at a time when it cannot find willing buyers for its portfolio securities or can only sell its portfolio securities at a material loss.

High yield bond risk: The risk that the issuer of bonds with ratings of Ba1 or lower by Moody's Investors Service, Inc. ("Moody's") or BB+ or lower by Standard & Poor's Financial Services LLC ("S&P") or Fitch Ratings, Inc. ("Fitch"), comparably rated by another nationally recognized statistical rating organization, or, if unrated, are determined to be of comparable quality by the Advisor, will default or otherwise be unable to honor a financial obligation (also known as lower-rated or "junk bonds"). These securities are considered to be predominately speculative with respect to an issuer's capacity to pay interest and repay principal in accordance with the terms of the obligations. Lower-rated bonds are more likely to be subject to an issuer's default or downgrade than investment grade (higher quality) bonds.

Foreign investing risk: The value of the Fund's investments in foreign securities may fall due to adverse political, social and economic developments abroad and due to decreases in foreign currency values relative to the US dollar. Investments in foreign government bonds involve special risks because the Fund may have limited legal recourse in the event of default. Also, foreign securities are sometimes less liquid and more difficult to sell and to value than securities of US issuers. These risks are greater for investments in emerging market issuers.

Emerging market risk: There are additional risks inherent in investing in less developed countries that are applicable to the Fund. Compared to the United States and other developed countries, investments in emerging market issuers may decline in value because of unfavorable foreign government actions, greater risks of political instability or the absence of accurate information about emerging market issuers. Further, emerging countries may have economies based on only a few industries and securities markets that trade only a small number of securities and employ settlement procedures

different from those used in the United States. Prices on these exchanges tend to be volatile and, in the past, securities in these countries have offered greater potential for gain (as well as loss) than securities of companies located in developed countries. Issuers may not be subject to uniform accounting, auditing and financial reporting standards and there may be less publicly available financial and other information about such issuers, comparable to US issuers. Further, investments by foreign investors are subject to a variety of restrictions in many emerging countries. Countries such as those in which the Fund may invest may experience high rates of inflation, high interest rates, exchange rate fluctuations or currency depreciation, large amounts of external debt, balance of payments and trade difficulties and extreme poverty and unemployment.

China risk: There are special risks associated with investments in China (including Chinese companies listed on US and Hong Kong exchanges), Hong Kong and Taiwan, including exposure to currency fluctuations, less liquidity, expropriation, confiscatory taxation, nationalization and exchange control regulations (including currency blockage). Inflation and rapid fluctuations in inflation and interest rates have had, and may continue to have, negative effects on the economy and securities markets of China, Hong Kong and Taiwan. In addition, investments in Taiwan and Hong Kong could be adversely affected by their respective political and economic relationship with China. China, Hong Kong and Taiwan are deemed by the investment manager to be emerging markets countries, which means an investment in these countries has more heightened risks than general foreign investing due to a lack of established legal, political, business and social frameworks and accounting standards or auditor oversight in these countries to support securities markets as well as the possibility for more widespread corruption and fraud. In addition, the standards for environmental, social and corporate governance matters in China, Hong Kong and Taiwan tend to be lower than such standards in more developed economies.

The Fund may invest in bonds issued by the People's Republic of China ("PRC") and certain other PRC-based entities which trade on the China interbank bond market ("CIBM") through the CIBM Direct Access Program or the China—Hong Kong Bond Connect program (the "Bond Connect Program"). The CIBM Direct Access Program and the Bond Connect Program may be subject to further interpretation and guidance and future developments may restrict or otherwise affect the Fund's investments or returns. There can be no assurance that the CIBM Direct Access Program will not be restricted, suspended or abolished. If such event occurs, the Fund's ability to invest in the CIBM through the CIBM Direct Access Program will be adversely affected, and if the Fund is unable to adequately access the CIBM through other means, the Fund's ability to achieve its investment objective will be adversely

affected. There also can be no assurance that further regulations will not affect the availability of securities in the Bond Connect Program, the frequency of redemptions or other limitations. Further, the necessary trading, settlement and information technology systems for the Bond Connect Program may not function properly, causing the Bond Connect Program to be disrupted. In addition, the application and interpretation of the laws and regulations of Hong Kong, the PRC, and the People's Bank of China and the rules, policies or guidelines published or applied by relevant regulators and exchanges in respect of the CIBM Direct Access Program and Bond Connect Program are uncertain, and they may have an adverse effect on the Fund's performance.

Additionally, emerging market countries, such as China, may subject the Fund's investments to a number of tax rules, and the application of many of those rules may be uncertain. Changes in applicable Chinese tax law could reduce the after-tax profits of the Fund, directly or indirectly, including by reducing the after-tax profits of companies in China in which the Fund invests. Uncertainties in Chinese tax rules could result in unexpected tax liabilities for the Fund.

Portfolio turnover risk: High portfolio turnover from frequent trading will increase the Fund's transaction costs and may increase the portion of the Fund's capital gains that are realized for tax purposes in any given year. The Fund does not restrict the frequency of trading in order to limit expenses or the tax effect that its distributions may have on shareholders.

Market risk: The risk that the market value of the Fund's investments may fluctuate, sometimes rapidly or unpredictably, as the stock and bond markets fluctuate. Market risk may affect a single issuer, industry, or sector of the economy, or it may affect the market as a whole.

Leverage risk associated with financial instruments: The use of financial instruments to increase potential returns, including derivatives used for investment (non-hedging) purposes, may cause the Fund to be more volatile than if it had not been leveraged. The use of leverage may also accelerate the velocity of losses and can result in losses to the Fund that exceed the amount originally invested.

underlying asset, rate, index or overall market securities. Derivatives relating to fixed income markets are especially susceptible to interest rate risk and credit risk. In addition, many types of swaps and other non-exchange traded derivatives may be subject to liquidity risk, credit risk and mispricing or valuation complexity. These derivatives risks are different from, and may be greater than, the risks associated with investing directly in securities and other instruments.

Preferred stock risk: Preferred stocks in which the Fund may invest are sensitive to interest rate changes. The rights of preferred stocks on the distribution of a company's assets in the event of a liquidation are generally subordinate to the rights associated with a company's debt securities.

Municipal securities risk: Municipal securities are subject to interest rate and credit risks. The ability of a municipal issuer to make payments and the value of municipal securities can be affected by uncertainties in the municipal securities market. Such uncertainties could cause increased volatility in the municipal securities market and could negatively impact the fund's net asset value and/or the distributions paid by the fund. Municipal bonds secured by revenues from public housing authorities may be subject to additional uncertainties relating to the possibility that proceeds may exceed supply of available mortgages to be purchased by public housing authorities, resulting in early retirement of bonds, or that homeowner repayments will create an irregular cash flow. Municipalities continue to experience difficulties in the current economic and political environment.

US Government securities risk: There are different types of US government securities with different levels of credit risk, including the risk of default, depending on the nature of the particular government support for that security. For example, a US government-sponsored entity, although chartered or sponsored by an Act of Congress, may issue securities that are neither insured nor guaranteed by the US Treasury and are therefore riskier than those that are.

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

Performance

Risk/return bar chart and table

The Fund's Class P shares acquired the assets and liabilities of Fort Dearborn Income Securities, Inc., a closed-end fund (the "Predecessor Fund"), prior to the opening of business on May 23, 2016 (the "Reorganization"). The Predecessor Fund was also managed by the Advisor, and, prior to June 13, 2022, the day-to-day management of, and investment decisions for, the Fund and the Predecessor Fund were made by the same portfolio management team. The Predecessor Fund and the Fund have substantially similar investment objectives and, pri-

or to June 13, 2022, had substantially similar strategies. Therefore, the information shown below for Class P shares reflects the historical performance of the Predecessor Fund for periods prior to the Reorganization.

The performance information that follows shows the Fund's performance information in a bar chart and an average annual total returns table. There is no performance information quoted for the Class P2 shares of the Fund as the Class P2 shares have not completed a full calendar year of operations as of the date of this prospectus. Returns for Class P2 shares will differ from the Class P shares to the extent that the Class P2 shares are subject to different expenses. The bar chart and average annual total returns table show the performance of the Predecessor Fund's performance adopted by the Class P shares of the Fund for periods prior to the Reorganization. The information provides some indication of the risks of investing in the Fund by showing changes in the Fund's performance from year to year and by showing how the Fund's average annual total returns compare with those of a broad measure of market performance. The performance information shown for periods prior to the Reorganization is for the Predecessor Fund and may not be representative of performance of the Fund. In June 2022, the Fund's investment strategies changed. The performance below for periods prior to that date is attributable to the Fund's performance before the strategy change. The index reflects no deduction for fees, expenses or taxes. The Fund's past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Updated performance for the Fund is available at https://www.ubs.com/us-mutualfundperformance.

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor's tax situation and may differ from those shown. In addition, the after-tax returns shown are not relevant to investors who hold Fund shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for the other classes will vary from the Class P shares' after-tax returns shown.

Total return (Class P)

Total return January 1 - March 31, 2022: (6.11)%
Best quarter during calendar years shown—2Q 2020: 4.78%
Worst quarter during calendar years shown—2Q 2013: (4.31)%

Average annual total returns (figures reflect sales charges)
(for the periods ended December 31, 2021)

Class (inception date)	1 year			5 years			10 years			Life of class
Class P (12/19/72) Return before taxes		(1.49	)%		3.56	%		3.09	%		7.32	%
Return after taxes on distributions		(2.24	)		2.51			1.60			3.87
Return after taxes on distributions and sale of fund shares		(0.88	)		2.27			1.77			3.87
Bloomberg US Aggregate Bond Index		(1.54	)		3.57			2.90			N/A

Investment advisor

UBS Asset Management (Americas) Inc. serves as the investment advisor to the Fund.

Portfolio managers

• Scott E. Dolan, portfolio manager of the Predecessor Fund since 2012 and of the Fund since its inception.

• Craig G. Ellinger, portfolio manager of the Predecessor Fund since 2012 and of the Fund since its inception.

• Jeffrey Haleen, portfolio manager of the Fund since 2018.

• Branimir Petranovic, portfolio manager of the Fund since 2018.

• David Kim, portfolio manager of the Fund since June 2022

Purchase & sale of Fund shares

Class P2 shares of the Fund are available for purchase on behalf of clients of a wrap fee program or other

Investment objective

The Fund seeks to provide long-term capital appreciation.

Fees and expenses

These tables describe the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. Shares of Class P2 are available for purchase on behalf of clients of a fee-based program or certain other advisory programs in which UBS Asset Management (Americas) Inc., the Fund's investment advisor and administrator ("UBS AM (Americas)" or the "Advisor") exercises investment discretion. Clients pay a wrap fee or a similar advisory fee to participate in such programs. Shares of Class P2 are also available for purchase on behalf of institutional clients with which the Advisor or its affiliates have signed a separate investment management agreement, pursuant to which such clients pay an advisory fee.

Shareholder fees (fees paid directly from your investment)

	Class P2
Maximum front-end sales charge (load) imposed on purchases (as a % of offering price)		None
Maximum contingent deferred sales charge (load) (CDSC) (as a % of purchase or sales price, whichever is less)		None

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

	Class P2
Management fees		0.85	%
Distribution and/or service (12b-1) fees		None
Other expenses¹		0.31
Acquired fund fees and expenses²		0.01
Total annual fund operating expenses		1.17
Less management fee waiver/expense reimbursements³		1.01
Total annual fund operating expenses after management fee waiver/expense reimbursements^2,3		0.16

¹ "Other expenses" are based on estimates for the current fiscal year.

²Since the "Acquired fund fees and expenses" are not directly borne by the Fund, they are not reflected in the Fund's financial statements, and therefore the amounts listed in "Total annual fund operating expenses" will differ from those presented in the Financial highlights.

³ The Trust, with respect to the Fund, and the Advisor, have entered into a written agreement pursuant to which the Advisor has agreed to waive its management fees and retained administration fees, and to reimburse expenses (excluding expenses incurred through investment in other investment companies, interest, taxes, brokerage commissions, dividend expense and security loan fees for securities sold short, and extraordinary expenses, such as proxy-related expenses) to the extent necessary so that the Fund's ordinary operating expenses (excluding expenses incurred through investment in other investment companies, interest, taxes, brokerage commissions, dividend expense and security loan fees for securities sold short, and extraordinary expenses, such as proxy-related expenses), through the period ending October 28, 2022, do not exceed 0.15% for Class P2 shares. Pursuant to the written agreement, the Advisor is entitled to be reimbursed for any fees it waives and expenses it reimburses to the extent such reimbursement can be made during the three years following the period during which such fee waivers and expense reimbursements were made, provided that the reimbursement of the Advisor by the Fund will not cause the Fund to exceed the lesser of any applicable expense limit that is in place for the Fund (i) at the time of the waiver or reimbursement or (ii) at the time of the recoupment. The fee waiver/expense reimbursement agreement may be terminated by the Fund's Board of Trustees at any time and also will terminate automatically upon the expiration or termination of the Fund's advisory contract with the Advisor. Upon termination of the fee waiver/expense reimbursement agreement, however, UBS AM (Americas)'s three year recoupment rights will survive.

Example

				1 year				3 years				5 years				10 years
Class P2				$	16			$	271			$	546			$	1,330

Portfolio turnover

The Fund pays transaction costs, such as mark-ups, when it buys and sells securities (or "turns over" its

portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund's performance. During the most recent fiscal year, the Fund's portfolio turnover rate was 63% of the average value of its portfolio.

Principal strategies
Principal investments

Under certain market conditions, the Fund may invest in companies at the time of their initial public offering ("IPO").

Management process

In selecting securities, the Advisor seeks to invest in companies that possess dominant market positions or franchises, a major technological edge, or a unique competitive advantage. To this end, the Advisor considers earnings revision trends, positive stock price momentum and sales acceleration when selecting securities. The Fund may invest in emerging growth companies, which are companies that the Advisor expects to experi-

ence above-average earnings or cash flow growth or meaningful changes in underlying asset values.

The Fund is classified by UBS AM (Americas) as an "ESG-integrated" fund. The Fund's investment process integrates material sustainability and/or environmental, social and governance ("ESG") considerations into the research process. ESG integration is driven by taking into account material ESG risks which could impact investment returns, rather than being driven by specific ethical principles or norms. The analysis of material sustainability/ESG considerations can include many different aspects, including, for example, the carbon footprint, employee health and well-being, supply chain management, fair customer treatment and governance processes of a company. The Fund's portfolio managers may still invest in securities with a higher ESG risk profile where the portfolio managers believe the potential compensation outweighs the risks identified.

Main risks

Small- and mid-capitalization risk: The risk that securities of smaller capitalization companies tend to be more volatile and less liquid than securities of larger capitalization companies. This can have a disproportionate effect on the market price of smaller capitalization companies and affect the Fund's ability to purchase or sell these securities. In general, smaller capitalization companies are more vulnerable than larger companies to adverse business or economic developments, and they may have more limited resources.

Market risk: The market value of the Fund's investments may fluctuate, sometimes rapidly or unpredictably, as the stock and bond markets fluctuate. Market risk may affect a single issuer, industry, or sector of the economy, or it may affect the market as a whole.

Focus risk: To the extent the Fund's investment strategy leads to sizable allocations to a particular market, sector or industry, the Fund may be more sensitive to any single economic, business, political, regulatory, or other event that occurs in that market, sector or industry. As a result, there may be more fluctuation in the price of the Fund's shares.

IPOs risk: The purchase of shares issued in IPOs may expose the Fund to the risks associated with issuers that have no operating history as public companies, as well

as to the risks associated with the sectors of the market in which the issuer operates. The market for IPO shares may be volatile, and share prices of newly-public companies may fluctuate significantly over a short period of time.

Foreign investing risk: The value of the Fund's investments in foreign securities may fall due to adverse political, social and economic developments abroad and due to decreases in foreign currency values relative to the US dollar. Also, foreign securities are sometimes less liquid and more difficult to sell and to value than securities of US issuers.

Real estate securities and REITs risk: The risk that the Fund's performance will be affected by adverse developments in the real estate industry. Real estate values may be affected by a variety of factors, including: local, national or global economic conditions; changes in zoning or other property-related laws; environmental regulations; interest rates; tax and insurance considerations; overbuilding; property taxes and operating expenses; or declining values in a neighborhood. Similarly, a REIT's performance depends on the types, values, locations and management of the properties it owns. In addition, a REIT may be more susceptible to adverse developments affecting a single project or market segment than a more diversified investment. Loss of status as a qualified REIT under the US federal tax laws could adversely affect the value of a particular REIT or the market for REITs as a whole.

Investing in ETFs risk: The Fund's investment in ETFs may subject the Fund to additional risks than if the Fund would have invested directly in the ETF's underlying securities. These risks include the possibility that an ETF may experience a lack of liquidity that can result in greater volatility than its underlying securities; an ETF may trade at a premium or discount to its net asset value; an ETF may not replicate exactly the performance of the benchmark index it seeks to track; trading an ETF's shares may be halted if the listing exchange's officials deem such action appropriate; and a passively managed ETF would not necessarily sell a security because the issuer of the security was in financial trouble unless the security is removed from the index that the ETF seeks to track. In addition, investing in an ETF may also be more costly than if a Fund had owned the underlying securities directly. The Fund, and indirectly, shareholders of the Fund, bear a proportionate share of the ETF's expenses, which include management and advisory fees and other expenses. In addition, the Fund will pay brokerage commissions in connection with the purchase and sale of shares of the ETF.

be more volatile than if it had not been leveraged. The use of leverage may also accelerate the velocity of losses and can result in losses to the Fund that exceed the amount originally invested.

Derivatives risk: The value of "derivatives"—so called because their value "derives" from the value of an underlying asset, reference rate or index—may rise or fall more rapidly than other investments. It is possible for the Fund to lose more than the amount it invested in the derivative. The risks of investing in derivative instruments also include market risk, management risk, counterparty risk (which is the risk that a counterparty to a derivative contract is unable or unwilling to meet its financial obligations) and the risk that changes in the value of a derivative may not correlate perfectly with the underlying asset, rate, index or overall market securities. In addition, non-exchange traded derivatives may be subject to liquidity risk, credit risk and mispricing or valuation complexity. These derivatives risks are different from, and may be greater than, the risks associated with investing directly in securities and other instruments.

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

Performance

Risk/return bar chart and table

Total return (Class P)

Total return January 1 - March 31, 2022: (9.98)%
Best quarter during calendar years shown—2Q 2020: 41.13%
Worst quarter during calendar years shown—4Q 2018: (24.27)%

Average annual total returns (figures reflect sales charges)
(for the periods ended December 31, 2021)

Class (inception date)	1 year			5 years			10 years
Class P (9/30/97) Return before taxes		5.22	%		20.16	%		17.03	%
Return after taxes on distributions		(1.04	)		15.62			13.79
Return after taxes on distributions and sale of fund shares		4.72			14.74			13.06
Russell 2000 Growth Index		2.83			14.53			14.14

Investment advisor

UBS Asset Management (Americas) Inc. serves as the investment advisor to the Fund.

Portfolio managers

• David Wabnik, portfolio manager of the Fund since its inception.

• Samuel Kim, portfolio manager of the Fund since 2011.

Investment objective, strategies, securities selection and risks

Fund objective

The Fund seeks to maximize total return, consisting of capital appreciation and current income.

Principal investment strategies

Under normal circumstances, the Fund invests at least 80% of its net assets (plus borrowings for investment purposes, if any) in bonds and/or instruments that provide exposure to bond markets.

Under normal circumstances, the Fund will invest at least 50% of its net assets in securities that, at the time of purchase, are rated investment grade by an independent rating agency, but may invest up to 50% in securities rated below investment grade (also known as lower-rated or "junk bonds"). Investment grade fixed income securities possess a minimum rating of Baa3 by Moody's or BBB- by S&P or Fitch, comparably rated by another nationally recognized statistical rating organization, or, if unrated, are determined by the Advisor to be of comparable quality.

cy, have coupons payable in any currency and may be of any maturity or duration.

The Fund may, but is not required to, use derivative instruments for risk management purposes or as part of the Fund's investment strategies. Generally, derivatives are financial contracts whose value depends upon, or is derived from, the value of an underlying asset, reference rate, index or other market factor and may relate to stocks, bonds, interest rates, credit, currencies or currency exchange rates, commodities and related indexes. Examples of derivatives include options (including, options on futures, forwards and swap agreements), futures, forward agreements, swap agreements (including, but not limited to, interest rate, total return, currency, credit default and inflation swaps), credit-linked securities and structured investments. The Fund may use derivatives to hedge against a specific security or currency; to manage or adjust the risk profile of the Fund; to earn income and enhance returns; to replace more traditional direct investments; to obtain exposure to certain markets; or to establish net short positions for individual sectors, markets, currencies or securities. The Fund may use options, futures, swap agreements, credit-linked securities and structured investments to adjust the Fund's portfolio duration.

The Fund may engage in active and frequent trading of portfolio securities to achieve its principal investment strategies.

The Fund will notify shareholders at least 60 days prior to any change in its policy of investing at least 80% of its net assets (plus borrowings for investment purposes, if any) in bonds and/or instruments that provide exposure to bond markets.

Securities selection

The investment process combines both a top-down and bottom-up dynamic approach to exploit diversified sources of alpha (that is, potential sources of return in excess of a base market rate). The Advisor makes active decisions related to top-down factors, including duration, yield curve, and sector positioning. "Duration" is a measure of price sensitivity of a fixed income investment or portfolio (expressed as % change in price) to a 1 percentage point (i.e., 100 basis points) change in interest rates, accounting for optionality in bonds such as prepayment risk and call/put features. A longer duration means an increased exposure to changes in interest rates. For example, when the level of interest rates increases by 0.10%, the price of a fixed income security or a portfolio of fixed income securities having a duration of five years generally will decrease by approximately 0.50%. Conversely, when the level of interest rates decreases by 0.10%, the price of a fixed income security or a portfolio of fixed income securities having a duration of five years generally will increase by approximately 0.50%. After defining these parameters, portfolio managers and credit research analysts work in close collaboration to develop investment themes for industry overweights and underweights as well as to determine the portions of the credit curve that are most attractive. The team then works to select securities to build optimal portfolios using bottom-up research and analysis.

The Fund may invest in cash or cash equivalent instruments, including shares of an affiliated investment company. When market or other conditions warrant, the Fund may make substantial temporary defensive investments in cash or cash equivalents that may be inconsistent with the Fund's principal investment strategies, which may affect the Fund's ability to pursue its investment objective. The Advisor actively manages the Fund. As such, the Fund may have high portfolio turnover, which may result in higher costs for transactions and taxable gains. The trading costs and tax effects associated with portfolio turnover may adversely affect the Fund's performance.

The Fund may lend its portfolio securities to generate additional income. The Fund may invest in other open-end investment companies advised by the Advisor to gain exposure to certain markets. The Fund does not pay advisory fees that are retained by the Advisor in connection with its investment in the investment companies advised by the Advisor, but may pay other expenses associated with such investments (such as sub-advisory fees paid to other parties, if any).

More about risks

An investment in the Fund is not guaranteed; you may lose money by investing in the Fund. The other risks presented by an investment in the Fund are:

• Interest rate risk—The risk that changing interest rates may adversely affect the value of an investment. An increase in prevailing interest rates typically causes the value of fixed income securities to fall, while a decline in prevailing interest rates may cause the market value of fixed income securities to rise. Changes in interest rates will affect the value of longer-term fixed income securities more than shorter-term securities and higher quality securities more than lower quality securities. Interest rate changes can be sudden and unpredictable, and are influenced by a number of factors including government policy, inflation expectations and supply and demand. A substantial increase in interest rates may have an adverse impact on the liquidity and valuation of a security, especially those with longer maturities. Changes in government monetary policy, including changes in tax policy or changes in a central bank's implementation of specific policy goals, may have a substantial impact on interest rates. There can be no guarantee that any particular government or central bank policy will be continued, discontinued or changed nor that any such policy will have the desired effect on interest rates. During periods when interest rates are low or there are negative interest rates, the Fund's performance may be negatively impacted, and the Fund may experience increased volatility of its net asset value per share.

Variable rate securities generally will not increase in market value if interest rates decline. Conversely, the market value may not decline when prevailing interest rates rise. Fixed rate debt securities generally are more sensitive to interest rate changes than variable rate securities.

• Credit and high yield bond risk—The risk that a bond issuer may default or otherwise be unable to honor a financial obligation, or may become less willing or less able to do so. Bonds with ratings of Ba1 or lower by Moody's or BB+ or lower by S&P or Fitch, comparably rated by another nationally recognized statistical rating organization or, if unrated, determined by the Advisor to be of comparable quality, may have increased risks of default (also known as lower-rated or "junk bonds"). These securities are considered to be predominately speculative with respect to an issuer's capacity to pay interest and repay principal in accordance with the terms of the obligations. Lower-rated bonds are more likely to be subject to an issuer's default or downgrade than investment grade (higher-rated) bonds.

• Mortgage- and asset-backed securities risk—The Fund may invest in mortgage- and asset-backed securities that are subject to prepayment or call risk, which is the risk that the borrower's payments may be received earlier or later than expected due to changes in prepayment rates on underlying loans. Faster prepayments often happen when interest rates are falling. As a result, the Fund may reinvest these early payments at lower interest rates, thereby reducing the Fund's income. Conversely, when interest rates rise, prepayments may happen more slowly, causing the security to lengthen in duration. Longer duration securities tend to be more volatile. Securities may be prepaid at a price less than the original purchase value. An unexpectedly high rate of defaults on the mortgages held by a mortgage pool may adversely affect the value of mortgage-backed securities and could result in losses to the Fund.

• Liquidity risk—The risk that the Fund may have difficulty or may not be able to sell its investments. Illiquidity may result from political, economic or issuer specific events; changes in a specific market's size or structure, including the number of participants; or overall market disruptions. When there is no willing buyer and investments cannot be readily sold at the desired time or price, the Fund may have to accept a lower price or may not be able to sell the security at all. An inability to sell securities can adversely affect the Fund's value or prevent the Fund from being able to take advantage of other investment opportunities. Liquid portfolio investments may become illiquid or less liquid after purchase by the Fund due to low

trading volume, adverse investor perceptions and/or other market developments. In recent years, the number and capacity of dealers that make markets in fixed income securities has decreased. Consequently, the decline in dealers engaging in market making trading activities may increase liquidity risk, which can be more pronounced in periods of market turmoil. Liquidity risk may be magnified in a rising interest rate environment or when investor redemptions from fixed income funds may be higher than normal, causing increased supply in the market due to selling activity. Liquidity risk includes the risk that the Fund will experience significant net redemptions at a time when it cannot find willing buyers for its portfolio securities or can only sell its portfolio securities at a material loss.

• Foreign investing risk—The risk that prices of the Fund's investments in foreign securities may go down because of unfavorable foreign government actions, political instability or the absence of accurate information about foreign issuers. In addition, political, diplomatic, or regional conflicts, terrorism or war, social and economic instability, and internal or external policies or economic sanctions limiting or restricting foreign investment, the movement of assets or other economic activity may affect the value and liquidity of foreign securities. Also, a decline in the value of foreign currencies relative to the US dollar will reduce the value of securities denominated in those currencies. Also, foreign securities are sometimes less liquid and harder to sell and to value than securities of US issuers. Each of these risks is more severe for securities of issuers in emerging market countries.

• Emerging market risk—There are additional risks inherent in investing in less developed countries that are applicable to the Fund. Compared to the United States and other developed countries, investments in emerging market issuers may decline in value because of unfavorable foreign government actions, greater risks of political instability or the absence of accurate information about emerging market issuers. Further, emerging countries may have economies based on only a few industries and securities markets that trade only a small number of securities and employ settlement procedures different from those used in the United States. Prices on these exchanges tend to be volatile and, in the past, securities in these countries have offered greater potential for gain (as well as loss) than securities of companies located in developed countries. Issuers may not be subject to uniform

accounting, auditing and financial reporting standards and there may be less publicly available financial and other information about such issuers, comparable to US issuers. Governments in emerging market countries are often less stable and more likely to take extra-legal action with respect to companies, industries, assets, or foreign ownership than those in more developed markets. Moreover, it can be more difficult for investors to bring litigation or enforce judgments against issuers in emerging markets or for US regulators to bring enforcement actions against such issuers. Further, investments by foreign investors are subject to a variety of restrictions in many emerging countries. Countries such as those in which the Fund may invest may experience high rates of inflation, high interest rates, exchange rate fluctuations or currency depreciation, large amounts of external debt, balance of payments and trade difficulties and extreme poverty and unemployment.

• China risk—There are special risks associated with investments in China (including Chinese companies listed on US and Hong Kong exchanges), Hong Kong and Taiwan, including exposure to currency fluctuations, less liquidity, expropriation, confiscatory taxation, nationalization and exchange control regulations (including currency blockage). Inflation and rapid fluctuations in inflation and interest rates have had, and may continue to have, negative effects on the economy and securities markets of China, Hong Kong and Taiwan. In addition, investments in Taiwan and Hong Kong could be adversely affected by their respective political and economic relationship with China. China, Hong Kong and Taiwan are deemed by the investment manager to be emerging markets countries, which means an investment in these countries has more heightened risks than general foreign investing due to a lack of established legal, political, business and social frameworks and accounting standards or auditor oversight in these countries to support securities markets as well as the possibility for more widespread corruption and fraud. In addition, the standards for environmental, social and corporate governance matters in China, Hong Kong and Taiwan tend to be lower than such standards in more developed economies.

Connect program (the "Bond Connect Program"). The CIBM Direct Access Program and the Bond Connect Program may be subject to further interpretation and guidance and future developments may restrict or otherwise affect the Fund's investments or returns. There can be no assurance that the CIBM Direct Access Program will not be restricted, suspended or abolished. If such event occurs, the Fund's ability to invest in the CIBM through the CIBM Direct Access Program will be adversely affected, and if the Fund is unable to adequately access the CIBM through other means, the Fund's ability to achieve its investment objective will be adversely affected. There also can be no assurance that further regulations will not affect the availability of securities in the Bond Connect Program, the frequency of redemptions or other limitations. Further, the necessary trading, settlement and information technology systems for the Bond Connect Program may not function properly, causing the Bond Connect Program to be disrupted. In addition, the application and interpretation of the laws and regulations of Hong Kong, the PRC, and the People's Bank of China and the rules, policies or guidelines published or applied by relevant regulators and exchanges in respect of the CIBM Direct Access Program and Bond Connect Program are uncertain, and they may have an adverse effect on the Fund's performance.

• Portfolio turnover risk—High portfolio turnover from frequent trading will increase the Fund's transaction costs and may increase the portion of the Fund's capital gains that are realized for tax purposes in any given year. This, in turn, may increase the Fund's taxable distributions in that year. Frequent trading also may increase the portion of the Fund's realized capital gains that is considered "short-term" for tax purposes. Shareholders will pay higher taxes on distributions that represent short-term capital gains than they would pay on distributions that represent long-term capital gains. The Fund does not restrict the frequency of trading in order to limit expenses or the tax effect that its distributions may have on shareholders.

• Market risk—The risk that the market value of the Fund's investments will fluctuate as the stock and fixed-income markets fluctuate. Market risk may affect a single issuer, industry or sector of the economy, or it may affect the market as a whole. In addition, turbulence in financial markets and reduced liquidity in equity and/or fixed-income markets may negatively affect the Fund. Global economies and financial markets are becoming increasingly interconnected, and conditions and events in one country, region or financial market may adversely impact issuers in a different country, region or financial market. These risks may be magnified if certain events or developments adversely interrupt the global supply chain, and could affect companies worldwide. Recent examples include pandemic risks related to COVID-19 and the aggressive measures taken worldwide in response by (i) governments, including closing borders, restricting travel and imposing prolonged quarantines of, or similar restrictions on, large populations, and (ii) businesses, including forced or voluntary closures, changes to operations and reductions of staff. The effects of COVID-19 have contributed to increased volatility in global financial markets and may affect certain countries, regions, companies, industries and market sectors more dramatically than others. The COVID-19 pandemic has had, and any other outbreak of an infectious disease or serious environmental or public health concern could have, a significant negative impact on economic and market conditions, could exacerbate pre-existing political, social and economic risks in certain countries or regions and could trigger a prolonged period of global economic slowdown, which may impact the Fund. It is not known how long the impact of the COVID-19 pandemic will, or future impacts of other significant events would, last or the severity thereof. To the extent the Fund is overweight in certain countries, regions, companies, industries or market sectors, such positions will increase the risk of loss from adverse developments affecting those countries, regions, companies, industries or sectors.

• Leverage risk associated with financial instruments—Certain derivatives that the Fund may use may create leverage. Derivatives that involve leverage can result in losses to the Fund that exceed the amount originally invested in the derivatives.

• Derivatives risk—Derivatives involve risks different from, and possibly greater than, the risks associated with investing directly in securities and other instruments. Derivatives require investment techniques and risk analyses different from those of other investments. If the Advisor incorrectly forecasts the value of securities, currencies, interest rates, or other economic factors in using derivatives, the Fund might have been in a better position if the Fund had not entered into the derivatives. While some strategies involving derivatives can protect against the risk of loss, the use of derivatives can also reduce the opportunity for gain or even result in losses by offsetting favorable price movements in other Fund investments. Derivatives also involve the risk of mispricing or improper valuation, the risk that changes in the value of a derivative may not correlate perfectly with the underlying asset, rate, index, or overall securities markets, and counterparty and credit risk (the risk that the other party to a swap agreement or other derivative will not fulfill its contractual obligations, whether because of bankruptcy or other default). With respect to futures and certain swaps, there is a risk of loss by the Fund of the initial and variation margin deposits in the event of bankruptcy of an FCM with which the Fund has an open position in a futures or swaps contract, or the central counterparty in a swap contract. The assets of the Fund may not be fully protected in the event of the bankruptcy of the FCM or central counterparty. The Fund is also subject to the risk that the FCM could use the Fund's assets to satisfy its own financial obligations or the payment obligations of another customer to the central counterparty. Credit risk of cleared swap participants is concentrated in a few clearinghouses, and the consequences of insolvency of a clearinghouse are not clear. Gains or losses involving some options, futures, and other derivatives may be substantial (for example, for some derivatives, it is possible for the Fund to lose more than the amount the Fund invested in the derivatives). Some derivatives tend to be more volatile than other investments, resulting in larger gains or losses in response to market changes. Derivatives are subject to a number of other risks, including liquidity risk (the possible lack of a secondary market for derivatives and the resulting inability of the Fund to sell or otherwise close out the derivatives) and interest rate risk (some derivatives are more sensitive to interest rate changes and market price fluctuations). The Fund's use of derivatives may

cause the Fund to realize higher amounts of short-term capital gains (generally taxed at ordinary income tax rates) than if the Fund had not used such instruments. Finally, the regulation of swaps and other derivatives is a rapidly changing area of law, and it is not possible to predict fully the effects of current or future regulation. It is possible that developments in government regulation of various types of derivatives could affect the character, timing and amount of the Fund's taxable income or gains; may limit or prevent the Fund from using or limit the Fund's use of these instruments effectively as a part of its investment strategy; and could adversely affect the Fund's ability to achieve its investment objective. The Fund's use of derivatives may be limited by the requirements for taxation of the Fund as a regulated investment company. New requirements, even if not directly applicable to the Fund, may increase the cost of the Fund's investments and cost of doing business, may limit the availability of derivatives or may otherwise adversely affect the value or performance of derivatives.

• Preferred stock risk—Preferred stocks in which the Fund may invest are sensitive to interest rate changes. The rights of preferred stocks on the distribution of a company's assets in the event of a liquidation are generally subordinate to the rights associated with a company's debt securities.

• Municipal securities risk—Municipal securities are subject to interest rate, credit, illiquidity and market and political risks. The ability of a municipal issuer to make payments and the value of municipal securities can be affected by uncertainties in the municipal securities market, including litigation, the strength of the local or national economy, the issuer's ability to raise revenues through tax or other means, and the bankruptcy of the issuer affecting the rights of municipal securities holders and budgetary constraints of local, state and federal governments upon which the issuer may be relying for funding. Municipal securities and issuers of municipal securities may be more susceptible to downgrade, default and bankruptcy as a result of economic stress. In addition, the municipal securities market can be significantly affected by political changes, including legislation or proposals at either the state or the federal level to eliminate or limit the tax-exempt status of municipal bond interest or the tax-exempt status of a municipal bond fund's dividends may otherwise make municipal bonds less

attractive in comparison to taxable bonds or other types of investments. Similarly, reductions in tax rates may make municipal securities less attractive in comparison to taxable bonds. Legislatures also may be unable or unwilling to appropriate funds needed to pay municipal securities obligations. These events can cause the value of the municipal securities held by a fund to fall and might adversely affect the tax-exempt status of a fund's investments or of the dividends that a fund pays.

Lower-rated municipal securities are subject to greater credit and market risk than higher quality municipal securities. In addition, third-party credit quality or liquidity enhancements are frequently a characteristic of the structure of municipal securities. Problems encountered by such third-parties (such as issues negatively impacting a municipal bond insurer or bank issuing a liquidity enhancement facility) may negatively impact a municipal security even though the related municipal issuer is not experiencing problems. Municipal bonds secured by revenues from public housing authorities may be subject to additional uncertainties relating to the possibility that proceeds may exceed supply of available mortgages to be purchased by public housing authorities, resulting in early retirement of bonds, or that homeowner repayments will create an irregular cash flow. Further, unlike many other types of securities, offerings of municipal securities traditionally have not been subject to regulation by, or registration with, the SEC, resulting in a relative lack of information about certain issuers of municipal securities.

• US Government securities risk—Credit risk is the risk that the issuer will not make principal or interest payments when they are due. There are different types of US government securities with different relative levels of credit risk depending on the nature of the particular government support for that security. US government securities may be supported by (i) the full faith and credit of the United States; (ii) the ability of the issuer to borrow from the US Treasury; (iii) the credit of the issuing agency, instrumentality or government-sponsored entity; (iv) pools of assets (e.g., mortgage-backed securities); or (v) the United States in some other way. In some cases, there is even the risk of default. For example, for asset backed securities there is the risk those assets will decrease in value below the face value of the security. Similarly, for cer-

tain agency-issued securities there is no guarantee the US government will support the agency if it is unable to meet its obligations. Further, the US government and its agencies and instrumentalities do not guarantee the market value of their securities; consequently, the value of such securities will fluctuate.

• LIBOR replacement risk—Certain variable- and floating- rate debt securities that the Fund may invest in are subject to rates that are tied to an interest rate, such as LIBOR. Although many LIBOR rates were phased out at the end of 2021 as originally intended, a selection of widely used USD LIBOR rates will continue to be published until June 2023 in order to assist with the transition. There remains uncertainty regarding the effect of the LIBOR transition process. Any impact of a transition away from LIBOR on the Fund, or the instruments in which the Fund invests, cannot yet be determined. Although the Federal Reserve Bank of New York has identified the Secured Overnight Financing Rate ("SOFR") as the intended replacement to USD LIBOR, foreign regulators have proposed other interbank offered rates, such as the Sterling Overnight Index Average ("SONIA"), and other replacement rates, which could also be adopted. The unavailability or replacement of LIBOR may affect the value, liquidity or return on certain Fund investments and may result in costs incurred in connection with closing out positions and entering into new trades. Any pricing adjustments to the Fund's investments resulting from a substitute reference rate may also adversely affect the Fund's performance and/or net asset value. Any such effects of the transition away from LIBOR and the adoption of alternative reference rates could result in losses to the Fund.

• Management risk—The risk that the investment strategies, techniques and risk analyses employed by the Advisor may not produce the desired results. The Advisor may be incorrect in its assessment of the value of securities or assessment of market or interest rate trends, which can result in losses to the Fund.

• Convertible bond risk—Convertible bonds are subject to the risks of equity securities when the underlying stock price is high relative to the conversion price (because more of the security's value resides in the conversion feature) and debt instruments when the underlying stock price is low relative to the conversion price (because the conversion feature is less valuable).

A convertible bond is not as sensitive to interest rate changes as a similar non-convertible debt instrument, and generally has less potential for gain or loss than the underlying equity security. The prices of equity securities fluctuate from time to time based on changes in the company's financial condition or overall market and economic conditions.

• Securities lending risk—Securities lending involves the lending of portfolio securities owned by the Fund to qualified broker-dealers and financial institutions who provide collateral to the Fund in connection with these loans. Securities lending involves the risk that the borrower may fail to return the securities in a timely manner or at all. As a result, the Fund may lose money and there may be a delay in recovering the loaned securities. The Fund also could lose money if it does not recover the securities and/or the value of the collateral falls, including the value of investments made with cash collateral. In some cases, these risks may be mitigated by an indemnification provided by the Fund's lending agent.

Other information

Exclusion of Advisor from commodity pool operator definition—With respect to the Fund, the Advisor has claimed an exclusion from the definition of a "commodity pool operator" ("CPO") under the Commodity Exchange Act ("CEA") and the rules of the US Commodity Futures Trading Commission ("CFTC") and, therefore, is not subject to CFTC registration or regulation as a CPO. In addition, the Advisor is relying upon a related exclusion from the definition of a "commodity trading advisor" ("CTA") under the CEA and the rules of the CFTC.

The terms of the CPO exclusion require the Fund, among other things, to adhere to certain limits on its investments in "commodity interests." Commodity interests include commodity futures, commodity options and swaps, which in turn include non-deliverable forward currency agreements, as further described in the Fund's SAI. Because the Advisor and the Fund intend to comply with the terms of the CPO exclusion at this time, the Fund will limit its investments in these types of instruments. The Fund is not intended as a vehicle for trading in the commodity futures, commodity options or swaps markets. The CFTC has neither reviewed nor approved the Advisor's reliance on these exclusions, or the Fund, its investment strategies or this prospectus.

Investment objective, strategies, securities selection and risks

Fund objective

The Fund seeks to provide long-term capital appreciation.

Principal investment strategies

Under normal circumstances, the Fund invests at least 80% of its net assets (plus borrowings for investment purposes, if any) in equity securities of US small capitalization companies. Small capitalization companies are those companies within the range of the largest and smallest company in the Russell 2000 Index at the time of purchase. However, the Fund may invest a portion of its assets in securities outside of this range. Further, if movement in the market price causes a security to no longer meet the small capitalization range, the Fund is not required to dispose of the security. As of May 6, 2022, the market capitalization range of the Russell 2000 Index was between $18 million and $14.3 billion. For purposes of the Fund's investments, US companies include any company organized outside of the United States but which: (a) is included in the Fund's benchmark index; (b) has its headquarters or principal location of operations in the United States; (c) whose primary listing is on a securities exchange or market in the United States; or (d) derives a majority of its revenues in the United States.

Investments in equity securities may include, but are not limited to, common stock and preferred stock, equity securities of REITs, and ETFs. The Fund may invest up to 20% of its net assets in foreign securities.

An ETF is a type of exchange-traded investment company. Ordinarily, the 1940 Act and the regulations promulgated thereunder prohibit an investment company from buying more than 3% of the shares of any other single investment company, investing more than 5% of its assets in any other single investment company, or investing more than 10% of its assets in other investment companies generally. However, provisions in an SEC exemptive regulation permit investment companies, such as the Fund, to acquire ETF securities in excess of the percentage limits of the 1940 Act and the Fund may rely on such exemptive regulation from time to time.

Under certain market conditions, the Fund may invest in companies at the time of their IPOs.

The Fund will notify shareholders at least 60 days prior to any change in its policy of investing at least 80% of its net assets (plus borrowings for investment purposes, if any) in equity securities of US small capitalization companies.

Securities selection

into account material ESG risks which could impact investment returns, rather than being driven by specific ethical principles or norms. The analysis of material sustainability/ESG considerations can include many different aspects, including, for example, the carbon footprint, employee health and well-being, supply chain management, fair customer treatment and governance processes of a company. The Fund's portfolio managers may still invest in securities with a higher ESG risk profile where the portfolio managers believe the potential compensation outweighs the risks identified.

The Fund may lend its portfolio securities to generate additional income.

More about risks

An investment in the Fund is not guaranteed; you may lose money by investing in the Fund. The other risks presented by an investment in the Fund are:

• Small- and mid-capitalization risk—The risk that investments in small and medium size companies may be more volatile than investments in larger companies, as small and medium size companies generally experience higher growth and failure rates. The trading volume of these securities is normally lower than that of larger companies. Such securities may be less liquid than others and could make it difficult to sell a security at a time or price desired. Changes in the demand for these securities generally have a disproportionate effect on their market price, tending to make prices rise more in response to buying demand and fall more in response to selling pressure.

and the aggressive measures taken worldwide in response by (i) governments, including closing borders, restricting travel and imposing prolonged quarantines of, or similar restrictions on, large populations, and (ii) businesses, including forced or voluntary closures, changes to operations and reductions of staff. The effects of COVID-19 have contributed to increased volatility in global financial markets and may affect certain countries, regions, companies, industries and market sectors more dramatically than others. The COVID-19 pandemic has had, and any other outbreak of an infectious disease or serious environmental or public health concern could have, a significant negative impact on economic and market conditions, could exacerbate pre-existing political, social and economic risks in certain countries or regions and could trigger a prolonged period of global economic slowdown, which may impact the Fund. It is not known how long the impact of the COVID-19 pandemic will, or future impacts of other significant events would, last or the severity thereof. To the extent the Fund is overweight in certain countries, regions, companies, industries or market sectors, such positions will increase the risk of loss from adverse developments affecting those countries, regions, companies, industries or sectors.

• Focus risk—To the extent the Fund's investment strategy leads to sizable allocations to a particular market, sector or industry, the Fund may be more sensitive to any single economic, business, political, regulatory, or other event that occurs in that market, sector or industry. As a result, there may be more fluctuation in the price of the Fund's shares.

• IPOs risk—The purchase of shares issued in IPOs exposes a fund to the risks associated with organizations that have little operating history as public companies, as well as to the risks associated with the sectors of the market in which the issuer operates. Further, the absence of a prior public market, unseasoned trading, the small number of shares usually available for trading or the possibility of dilution of share value by issuance of additional shares may affect the market value of IPO shares. The market for IPO shares has been volatile, and share prices of newly public companies have fluctuated significantly over short periods of time.

• Foreign investing risk—The risk that prices of the Fund's investments in foreign securities may go

down because of unfavorable foreign government actions, political instability or the absence of accurate information about foreign issuers. In addition, political, diplomatic, or regional conflicts, terrorism or war, social and economic instability, and internal or external policies or economic sanctions limiting or restricting foreign investment, the movement of assets or other economic activity may affect the value and liquidity of foreign securities. Also, a decline in the value of foreign currencies relative to the US dollar will reduce the value of securities denominated in those currencies. Also, foreign securities are sometimes less liquid and harder to sell and to value than securities of US issuers.

• Real estate securities and REITs risk—The risk that the Fund's performance will be affected by adverse developments in the real estate industry. Real estate values may be affected by a variety of factors, including: local, national or global economic conditions; changes in zoning or other property-related laws; environmental regulations; interest rates; tax and insurance considerations; overbuilding; property taxes and operating expenses; or declining values in a neighborhood. Similarly, a REIT's performance depends on the types, values, locations and management of the properties it owns. In addition, a REIT may be more susceptible to adverse developments affecting a single project or market segment than a more diversified investment. Loss of status as a qualified REIT under the US federal tax laws could adversely affect the value of a particular REIT or the market for REITs as a whole.

• Investing in ETFs risk—The Fund's investment in ETFs may subject the Fund to additional risks than if the Fund would have invested directly in the ETF's underlying securities. While the risks of owning shares of an ETF generally reflect the risks of owning the underlying securities the ETF is designed to track, lack of liquidity in an ETF can result in its value being more volatile than the underlying portfolio securities. In addition, shares of ETFs typically trade on securities exchanges, which may subject the Fund to the risk that an ETF in which the Fund invests may trade at a premium or discount to its net asset value and that trading an ETF's shares may be halted if the listing exchange's officials deem such action appropriate. Also, an ETF may not replicate exactly the performance of the benchmark index it seeks to track for a

number of reasons, including transaction costs incurred by the ETF, the temporary unavailability of certain index securities in the secondary market or discrepancies between the ETF and the index with respect to the weighting or number of instruments held by the ETF. In addition, a passively managed ETF would not necessarily sell a security because the issuer of the security was in financial trouble unless the security is removed from the index that the ETF seeks to track. Investing in an ETF may also be more costly than if a Fund had owned the underlying securities directly. The Fund, and indirectly, shareholders of the Fund, bear a proportionate share of the ETF's expenses, which include management and advisory fees and other expenses. In addition, the Fund will pay brokerage commissions in connection with the purchase and sale of shares of ETFs.

of the Fund may not be fully protected in the event of the bankruptcy of the FCM or central counterparty. The Fund is also subject to the risk that the FCM could use the Fund's assets to satisfy its own financial obligations or the payment obligations of another customer to the central counterparty. Gains or losses involving some options, futures, and other derivatives may be substantial (for example, for some derivatives, it is possible for the Fund to lose more than the amount the Fund invested in the derivatives). Some derivatives tend to be more volatile than other investments, resulting in larger gains or losses in response to market changes. Derivatives are subject to a number of other risks, including liquidity risk (the possible lack of a secondary market for derivatives and the resulting inability of the Fund to sell or otherwise close out the derivatives) and interest rate risk (some derivatives are more sensitive to interest rate changes and market price fluctuations). The Fund's use of derivatives may cause the Fund to realize higher amounts of short-term capital gains (generally taxed at ordinary income tax rates) than if the Fund had not used such instruments. Finally, the regulation of derivatives is a rapidly changing area of law, and it is not possible to predict fully the effects of current or future regulation. It is possible that developments in government regulation of various types of derivatives could affect the character, timing and amount of the Fund's taxable income or gains; may limit or prevent the Fund from using or limit the Fund's use of these instruments effectively as a part of its investment strategy; and could adversely affect the Fund's ability to achieve its investment objective. The Fund's use of derivatives may be limited by the requirements for taxation of the Fund as a regulated investment company. New requirements, even if not directly applicable to the Fund, may increase the cost of the Fund's investments and cost of doing business, may limit the availability of derivatives or may otherwise adversely affect the value or performance of derivatives.

• Securities lending risk—Securities lending involves the lending of portfolio securities owned by the Fund to qualified broker-dealers and financial institutions who

provide collateral to the Fund in connection with these loans. Securities lending involves the risk that the borrower may fail to return the securities in a timely manner or at all. As a result, the Fund may lose money and there may be a delay in recovering the loaned securities. The Fund also could lose money if it does not recover the securities and/or the value of the collateral falls, including the value of investments made with cash collateral. In some cases, these risks may be mitigated by an indemnification provided by the Fund's lending agent.

• Management risk—The risk that the investment strategies, techniques and risk analyses employed by the Advisor may not produce the desired results. The Advisor may be incorrect in its assessment of the value of securities or assessment of market trends, which can result in losses to the Fund.

Other information

Exclusion of Advisor from commodity pool operator definition—With respect to the Fund, the Fund's Advisor has claimed an exclusion from the definition of a CPO under the CEA and the rules of the CFTC and, therefore, is not subject to CFTC registration or regulation as a CPO. In addition, the Advisor is relying upon a related exclusion from the definition of a CTA under the CEA and the rules of the CFTC.

Managing your fund account

Flexible pricing

Each Fund offers three classes of shares—Class A, Class P, and Class P2. Each class has different sales charges and ongoing expenses. You can choose the class that is best for you, based on how much you plan to invest in a fund and how long you plan to hold your fund shares, the expenses of the share class and whether you qualify for a reduction or waiver of an applicable sales charge. Class P2 shares are available only to certain types of investors. Only Class P2 shares are offered in this prospectus.

Class P2 shares

Shareholders pay no front-end or deferred sales charges on Class P2 shares.

Class P2 shares do not pay ongoing 12b-1 distribution or service fees.

Buying shares

Class P2 shares of the Funds are available for purchase on behalf of clients of a wrap fee program or other advisory programs in which the Advisor exercises investment discretion. There are no minimum investment requirements for purchases on behalf of clients in such programs. Shares of Class P2 are also available for purchase on behalf of institutional clients with which the Advisor or its affiliates has signed a separate investment management agreement, pursuant to which such clients pay an advisory fee. For such institutional clients, the required minimum initial investment is $25 million, except that UBS AM (US) may waive the minimum for institutional clients at UBS AM (US)'s sole discretion. Other registered investment companies managed by the Advisor also may purchase Class P2 shares of the Funds, subject to no minimum investment requirements.

Shareholders that no longer participate in a wrap fee program or other advisory programs in which the Advisor exercises investment discretion may not buy any additional Class P2 shares (except through dividend reinvestments) unless such shareholder otherwise meets eligibility requirements of the share class. Additionally, for institutional clients, shares will be redeemed when your investment management agreement is terminated.

The Funds and UBS AM (US) reserve the right to reject a purchase order or suspend the offering of shares.

Market timers

The interests of the Funds' long-term shareholders and their ability to manage their investments may be adversely affected when the Funds' shares are repeatedly bought and sold in response to short-term market fluctuations—also known as "market timing." Market timing may cause a Fund to have difficulty implementing long-term investment strategies, because it cannot predict how much cash it will have to invest. Market timing also may force a Fund to sell portfolio securities at disadvantageous times to raise the cash needed to buy a market timer's Fund shares. Market timing also may materially increase a Fund's transaction costs, administrative costs or taxes. These factors may hurt a Fund's performance and its shareholders.

Class P2 shares of the Funds are used for separately managed accounts advised or sub-advised by the Advisor or its affiliates, on behalf of institutional clients with which the Advisor or its affiliates have signed a separate investment management agreement, and by other registered investment companies managed by the Advisor. Decisions as to whether to invest assets of a managed account, or invest assets on behalf of an institutional client, in Class P2 shares of the Funds will be made by the Advisor. Because Class P2 shares of the Fund are used as components of "wrap" accounts, Class P2 shares may be purchased or redeemed on a frequent basis for rebalancing purposes.

In addition, the nature of a Fund's portfolio holdings may allow a shareholder to engage in a short-term trading strategy to take advantage of possible delays between the change in the Fund's portfolio holdings and the reflection of that change in the Fund's net asset value (often called "arbitrage market timing"). Such a delay may occur if a Fund has significant investments in non-US securities, where due to time zone differences, the value of those securities is established some time before the Fund calculates its net asset value. In such circumstances, the available market prices for such non-US securities may not accurately reflect the latest indications of value at the time the Fund calculates its net asset value. A Fund also may be subject to arbitrage market timing because the Fund may have significant holdings in smaller cap securities, which may have market prices that do not accurately reflect the latest indications of value of these securities at the time that the Fund calculates its net asset value due to, among other reasons, infrequent trading or illiquidity. There is a possibility that arbitrage market timing may dilute the value

of Fund shares if redeeming shareholders receive proceeds (and buying shareholders receive shares) based upon a net asset value that does not reflect appropriate fair value prices. One of the objectives of the Funds' fair value pricing procedures is to minimize the possibilities of this type of arbitrage market timing.

The Board of Trustees of the Trust has adopted the following policies as a means to discourage, detect and prevent market timing. A Fund will reject purchase orders and exchanges into the Fund by any person, group or account that UBS AM (Americas), as the Funds' Advisor and Administrator, determines to be a market timer. UBS AM (Americas) maintains market timing prevention procedures under which it reviews daily reports from the Funds' transfer agent of all accounts that engaged in transactions in Fund shares that exceed a specified monetary threshold and effected such transactions within a certain period of time to evaluate whether any such account had engaged in market timing activity. In evaluating the account transactions, UBS AM (Americas) will consider the potential harm of the trading or exchange activity to a Fund or its shareholders. If UBS AM (Americas) determines, in its sole discretion, that a shareholder has engaged in market timing, the shareholder will be permanently barred from making future purchases or exchanges into the Funds. Additionally, in making a determination as to whether a shareholder has engaged in market timing, the shareholder's account may be temporarily barred from making additional investments into a Fund pending a definitive determination. In addition, if a Financial Advisor is identified as the Financial Advisor of two or more accounts that have engaged in market timing, UBS AM (Americas) may prohibit the Financial Advisor from making additional purchases of the Fund on behalf of its clients.

Shares of the Funds may be held through omnibus account arrangements, whereby a broker-dealer, investment advisor, retirement plan sponsor or other financial intermediary (each a "Financial Intermediary") maintains an omnibus account with the Funds for trading on behalf of its customers or participants. Omnibus accounts are accounts that aggregate the transactions of underlying shareholders, thus making it difficult to identify individual underlying account holder activity. If UBS AM (Americas) detects an unusual pattern of trading activity, UBS AM (Americas) will notify the Financial Intermediary of the omnibus account and will generally request that the Financial Intermediary provide underlying account

detail. If UBS AM (Americas) identifies market timing activity, it generally will instruct the Financial Intermediary to block the customer or participant from further purchases of Fund shares. In the event that the Financial Intermediary is unable to identify and block the customer or participant, UBS AM (Americas) generally will require the Financial Intermediary to block the particular plan from further purchases of Fund shares or instruct the Funds' transfer agent to block all purchases and exchange purchase orders from the Financial Intermediary. UBS AM (Americas) may periodically request underlying account detail for omnibus accounts for review and analysis.

While the Funds will seek to take actions (directly and with the assistance of Financial Intermediaries) that will detect market timing, the Funds' efforts may not be completely successful in minimizing or eliminating such trading activity.

Certain types of transactions are generally exempt from the market timing prevention procedures. These exempt transactions include redemptions through the Automatic Cash Withdrawal Plan, purchases through an automatic investment plan, purchases and redemptions by wrap fee accounts that have an automatic rebalancing feature and that have been identified to the Funds' distributor and transfer agent, purchases and redemptions on behalf of clients of a fee based advisory program or certain other advisory programs in which UBS AM (Americas) exercises investment discretion, purchases and redemptions on behalf of institutional clients with which UBS AM (Americas) has signed an investment management agreement and exercises investment discretion on behalf of such client, purchases and redemptions below a specified monetary threshold by institutional clients with which UBS AM (Americas) has signed a separate investment management agreement, and purchases and redemptions by other registered investment companies managed by the Advisor.

Selling shares

You can sell your Fund shares at any time.

In addition, shares will be redeemed when you terminate your managed account or, for institutional clients, your investment management agreement. In addition, shares will be redeemed or will be required by the shareholder's financial intermediary to convert to Class P shares of the Fund when you terminate your managed account, which may result in a taxable event. Such

exchanges will occur at the net asset value per share, without requiring any investment minimum to be met and without the imposition of any fees or other charges. Please contact your investment professional for further information.

Each Fund typically expects to pay sale proceeds to redeeming shareholders within 1-3 business days following receipt of a shareholder redemption order for those payments made to your account held with a financial institution; however, a Fund may take up to 7 days to pay sale proceeds. For sale proceeds that are paid directly to a shareholder by a Fund, the Fund typically expects to pay proceeds by wire, ACH, or mailing a check to redeeming shareholders within one business day following receipt of the shareholder redemption order; however, a Fund may take up to 7 days to pay sale proceeds.

Typically, redemptions of Fund shares will be made in cash. Each Fund typically expects to meet redemption requests by using holdings of cash or cash equivalents and/or proceeds from the sale of portfolio holdings. On a less regular basis, a Fund also may draw on a bank line of credit to meet redemption requests. In addition, under stressed market conditions or a particularly large redemption, a Fund may distribute redemption proceeds in-kind (instead of cash) to meet redemption requests, as described below.

Although not routinely used by the Funds, each Fund reserves the right to pay redemptions "in kind" (i.e., payment in securities rather than cash) if the investment you are redeeming is large enough to affect a Fund's operations or in particularly stressed market conditions. In these cases, you might incur brokerage or other costs converting the securities to cash. The securities included in a redemption in kind may include illiquid investments that may not be immediately saleable.

To help the government fight the funding of terrorism and money laundering activities, federal law requires all financial institutions to obtain, verify and record information that identifies each person who opens an account. If you do not provide the information requested, a Fund may not be able to maintain your account. If a Fund is unable to verify your identity (or that of another person(s) authorized to act on your behalf) within a reasonable time, the Fund and UBS AM (US) reserve the right to close your account and/or take such other action they deem reasonable or required by law. If

we decide to close your account for this reason, your fund shares will be redeemed at the net asset value per share next calculated after the account is closed, less any applicable fees. You may recognize a gain or loss on the redemption of your Fund shares and you may incur a tax liability.

Exchanging shares

You may exchange Class P2 shares of a Fund for shares of the same class of most other Family Funds.

Other Family Funds may have different minimum investment amounts. You may not be able to exchange your shares if the value of shares you exchange is not as large as the minimum investment amount in that other fund. Further, other Family Funds may have different eligibility requirements for purchase. You may not be able to exchange your shares if you are not eligible to purchase shares of the other Family Fund.

You may exchange shares of one fund for shares of another Family Fund only after the first purchase has settled and the first fund has received your payment.

The Funds may modify or terminate the exchange privilege at any time.

Pricing and valuation

The price at which you may buy, sell or exchange Fund shares is based on net asset value per share. Each Fund generally calculates its net asset value on days that the New York Stock Exchange ("NYSE") is open. A Fund calculates net asset value separately for each class as of the close of regular trading on the NYSE (generally, 4:00 p.m., Eastern time). The NYSE normally is not open, and the Funds do not price their shares, on most national holidays and on Good Friday. To the extent that a Fund's assets are traded in other markets on days when the NYSE is not open, the value of a Fund's assets may be affected on those days. If trading on the NYSE is halted for the day before 4:00 p.m., Eastern time, a Fund's net asset value per share generally will still be calculated as of the close of regular trading on the NYSE. The time at which a Fund calculates its net asset value and until which purchase, sale or exchange orders are accepted may be changed as permitted by the SEC.

Your price for buying, selling or exchanging shares will be based on the net asset value (adjusted for any applicable sales charges) that is next calculated after a Fund

receives your order in good form. If you place your order on a day the NYSE is not open, your price for buying, selling or exchanging shares will be based on the net asset value (adjusted for any applicable sales charges) that is calculated on the next day that the NYSE is open. If you place your order through a financial institution, your financial advisor is responsible for making sure that your order is promptly sent to the Fund.

Each Fund calculates its net asset value based on the current market value, where available, for its portfolio investments. The Funds normally obtain market values for their investments from independent pricing sources and broker-dealers. Independent pricing sources may use reported last sale prices, official market closing prices, current market quotations or valuations from computerized "evaluation" systems that derive values based on comparable investments. An evaluation system incorporates parameters such as security quality, maturity and coupon, and/or research and evaluations by its staff, including review of broker-dealer market price quotations, if available, in determining the valuation of the portfolio investments. If a market value is not readily available from an independent pricing source for a particular investment, that investment is valued at fair value as determined in good faith by or under the direction of the Trust's Board of Trustees.

The amortized cost method of valuation, which approximates market value, generally is used to value short-term debt instruments with 60 days or less remaining to maturity, unless the Board (or its delegate) determines that this does not represent fair value. Investments in open-end investment companies are valued at the daily closing net asset value of the respective investment company. Investments in non-registered investment companies are also valued at the daily net asset value. Pursuant to the Funds' use of the practical expedient within ASC Topic 820, investments in investment companies without publicly published prices are also valued at the daily net asset value. All investments quoted in foreign currencies are valued daily in US dollars on the basis of the foreign currency exchange rates prevailing at the time such valuation is determined by the Funds' custodian. Foreign currency exchange rates are generally determined as of the close of the NYSE.

Investments traded in the over-the-counter ("OTC") market and listed on The NASDAQ Stock Market, Inc. ("NASDAQ") normally are valued at the NASDAQ Official Closing Price. Other OTC securities are normally

valued at the last bid price on the valuation date available prior to valuation. Investments that are listed on US and foreign stock exchanges normally are valued at the market closing price, the last sale price on the day the securities are valued or, lacking any sales on such day, at the last available bid price.

The Trust's Board of Trustees has delegated to the Equities, Fixed Income, and Multi-Asset Valuation Committee of the Advisor the responsibility for making fair value determinations with respect to the Funds' portfolio holdings. The types of investments for which such fair value pricing may be necessary include, but are not limited to: foreign investments under some circumstances, as discussed below; investments of an issuer that has entered into a restructuring; investments whose trading has been halted or suspended; fixed-income securities that are in default and for which there is no current market value quotation; and investments that are restricted as to transfer or resale. The need to fair value the Funds' portfolio investments may also result from low trading volume in foreign markets or thinly traded domestic investments, and when a security subject to a trading limit or collar on the exchange or market on which it is primarily traded reaches the "limit up" or "limit down" price and no trading has taken place at that price. Various factors may be reviewed in order to make a good faith determination of an investment's fair value. These factors include, but are not limited to, fundamental analytical data relating to the investment; the nature and duration of restrictions on disposition of the investments; and the evaluation of forces that influence the market in which the investments are purchased and sold.

Each Fund expects to price most of its portfolio investments based on current market value, as discussed previously. Investments for which market quotations are not readily available may be valued based upon appraisals received from a pricing service using a computerized evaluation system or formula method that takes into consideration market indices, matrices, yield curves and other specific adjustments. This may result in the investments being valued at a price different from the price that would have been determined had the evaluation or formula method not been used. Investments also may be valued based on appraisals derived from information concerning the investment or similar investments received from recognized dealers in those holdings. If a Fund concludes that a market quotation is not readily available for a portfolio investment for any number of

reasons, including the occurrence of a "significant event" (e.g., natural disaster or governmental action), after the close of trading in its principal domestic or foreign market but before the close of regular trading on the NYSE, the Fund may use fair value methods to reflect those events. This policy is intended to assure that each Fund's net asset value fairly reflects the value of its portfolio holdings as of the time of pricing. Certain Funds may use a systematic fair valuation model provided by an independent third party to value investments principally traded in foreign markets in order to adjust for possible stale pricing that may occur between the close of the foreign exchanges and the time for valuation. The systematic fair valuation model may use calculations based on indices of domestic securities and other appropriate indicators, such as prices of relevant American Depositary Receipts and futures contracts. If an investment is valued at a "fair value," that value is likely to be different from the last quoted market price for the investment. In cases where investments are traded on more than one exchange, the investments are valued on the exchange designated as the primary market by UBS AM (Americas), the investment advisor of the Funds.

Valuing investments at fair value involves greater reliance on judgment than valuing investments that have readily available market quotations. Fair value determinations can also involve reliance on quantitative models employed by a fair value pricing service. There can be no assurance that a Fund could obtain the fair value assigned to an investment if it were to sell the investment at approximately the time at which the Fund determines its net asset value per share. As a result, a Fund's sale or redemption of its shares at net asset value, at a time when a holding or holdings are valued at fair value, may have the effect of diluting or increasing the economic interest of existing shareholders.

Each Fund may invest in investments that trade primarily in foreign markets that trade on weekends or other days on which the Funds do not calculate their net asset value. As a result, the Fund's net asset value may change on days when you will not be able to buy and sell your Fund shares. Certain investments in which the Funds invest are traded in markets that close before 4:00 p.m., Eastern time. Normally, developments that occur between the close of the foreign markets and 4:00 p.m., Eastern time, will not be reflected in the Fund's net asset value. However, if either of the Funds determine that such developments are so significant that they will materially affect the value of the Fund's

investments, the Fund may adjust the previous closing prices to reflect what is believed to be the fair value of these investments as of 4:00 p.m., Eastern time.

Futures contracts are generally valued at the settlement price established each day on the exchange on which they are traded. Forward foreign currency contracts are valued daily using forward exchange rates quoted by independent pricing services. Swaps are marked-to-market daily based upon values from third party vendors or quotations from market makers to the extent available and the change in value, if any, is recorded as an unrealized gain or loss on the Statement of assets and liabilities. In the event that market quotations are not readily available or deemed unreliable, the swap is valued at fair value as determined in good faith by or under the direction of the Board (or a committee designated by it).

A Fund's portfolio holdings may also consist of shares of other investment companies in which the Fund invests. The value of each such investment company will be its net asset value at the time the Fund's shares are priced. Each investment company calculates its net asset value based on the current market value for its portfolio holdings. Each investment company values securities and other instruments in a manner as described in that investment company's prospectus or offering document.

In December 2020, the SEC adopted Rule 2a-5 under the 1940 Act, which is intended to address valuation practices and the role of a fund's board with respect to the fair value of the investments of a registered investment company or business development company. Rule 2a-5, among other things, establishes an updated regulatory framework for the valuation practices of registered investment companies. The Funds will be required to comply with Rule 2a-5 starting in September 2022.

Management

Investment advisor

UBS Asset Management (Americas) Inc. ("UBS AM (Americas)"or the "Advisor") is a Delaware corporation with its principal business offices located at One North Wacker Drive, Chicago, IL 60606 and at 787 Seventh Avenue, New York, NY, 10019. UBS AM (Americas) is an investment advisor registered with the SEC. UBS AM (Americas) serves as the investment advisor to the Funds by managing the investment of assets of each Fund. As

of March 31, 2022, the Advisor had approximately $290.6 billion in assets under management. The Advisor is an indirect asset management subsidiary of UBS Group AG and a member of the UBS Asset Management Division, which had approximately $1.2 trillion in assets under management as of March 31, 2022. UBS is an internationally diversified organization headquartered in Zurich, Switzerland, with operations in many areas of the financial services group of industries.

Portfolio management

The Advisor's investment professionals are organized into investment management teams, with a particular team dedicated to a specific asset class. Information is provided below for those portfolio managers within each investment management team that are primarily responsible for coordinating the day-to-day management of each Fund.

UBS Multi Income Bond Fund

Scott E. Dolan, Craig G. Ellinger, Jeffrey Haleen, David Kim, and Branimir Petranovic are the members of the investment management team and are jointly and primarily responsible for the day-to-day management of the Fund's portfolio. Messrs. Dolan, Ellinger, Haleen, Kim and Petranovic have access to a globally integrated team of credit analysts and other members of the Fixed Income investment management team who may contribute to research, security selection and portfolio construction. Messrs. Dolan, Ellinger, Haleen, Kim and Petranovic are responsible for the overall portfolio and for reviewing the overall composition of the portfolio in an effort to ensure its compliance with the Fund's stated investment objective and strategies. Information about Messrs. Dolan, Ellinger, Haleen, Kim and Petranovic is provided below.

Scott E. Dolan is Head of US Multi-Sector Fixed Income and a Managing Director at UBS Asset Management. Prior to joining UBS Asset Management in 2008, Mr. Dolan was a managing director and head of securitized assets for Citigroup Alternative Investments. Prior to joining Citigroup, Mr. Dolan was a managing director and head of mortgages and structured assets for Bear Stearns Asset Management and a senior mortgage trader at the Clinton Group. Mr. Dolan also worked at Deutsche Asset Management as a managing director and co-head of the Rates Group responsible for strategy, security selection and trading for MBS, ABS, agencies and treasuries. Mr. Dolan started his career at Scudder, Stevens and Clark, where he managed total return fixed

income mutual funds and institutional portfolios. Mr. Dolan has been a portfolio manager of the Predecessor Fund since 2012 and of the Fund since its inception.

Craig G. Ellinger is Head of Americas Fixed Income and a Managing Director at UBS Asset Management. Mr. Ellinger has been an investment professional with UBS Asset Management since 2000 and a portfolio manager of the Predecessor Fund since 2012 and of the Fund since its inception.

Jeffrey Haleen is a Senior Portfolio Manager on the US Multi-Sector Fixed Income team and an Executive Director at UBS Asset Management. Prior to joining UBS Asset Management, Mr. Haleen was a trader for Deutsche Bank's London-based principal finance subsidiary, Winchester Capital, prior to which he was Head of Asset-Backed Securities Credit at Deerfield Capital Management. Mr. Haleen has been a portfolio manager of the Fund since 2018.

Branimir Petranovic is a Senior Portfolio Manager on the US Multi-Sector Fixed Income Team and an Executive Director at UBS Asset Management. Prior to joining UBS Asset Management, Mr. Petranovic managed fund of hedge fund portfolios at HFR Asset Management, prior to which he worked in the fixed income divisions at Goldman, Sachs & Co. and Scotia Capital. Mr. Petranovic has been a portfolio manager of the Fund since 2018.

David Kim is a Senior Portfolio Manager on the Multi-Sector Fixed Income team and an Executive Director at UBS Asset Management. Prior to joining UBS Asset Management, Mr. Kim worked at Goldman Sachs in the Equity Derivatives Group. Mr. Kim has been a portfolio manager of the Fund since June 2022.

UBS U.S. Small Cap Growth Fund

David Wabnik and Samuel Kim are the portfolio managers for the UBS U.S. Small Cap Growth Fund and are primarily responsible for the day-to-day management of the Fund's portfolio. All members of the U.S. Small Cap Growth investment team have responsibility for investment research. The portfolio managers have access to additional investment teams within the various asset classes and markets in which the Fund invests. Information about Messrs. Wabnik and Kim is provided below.

	Effective gross advisory fee as of			Advisory fee breakpoint schedule
Fund	June 30, 2021			Assets under management	Fee
UBS Multi Income Bond Fund¹		0.50	%	First $250 million		0.500	%
				On the next $250 million – $500 million		0.490
				On the next $500 million – $750 million		0.480
				Above $750 million		0.470
UBS U.S. Small Cap Growth Fund²		0.85	%	First $250 million		0.850	%
				On the next $250 million – $500 million		0.825
				On the next $500 million – $750 million		0.800
				On the next $750 million – $1 billion		0.775
				On the next $1 billion – $2 billion		0.725
				Above $2 billion		0.700

¹Prior to June 13, 2022, the investment advisory fee payable to the Advisor, before fee waivers and/or expense reimbursements, by the Fund was: 0.50% on all assets under management.

² Prior to June 13, 2022, the investment advisory fee payable to the Advisor, before fee waivers and/or expense reimbursements, by the Fund was: 0.850% on the first $1 billion assets under management and 0.825% on assets under management above $1 billion.

Administrator

UBS AM (Americas) is also the administrator of the Funds. Each Fund pays UBS AM (Americas) an annual contract rate of 0.075% of its average daily net assets for administrative services, before fee waivers and/or expense reimbursements, if any.

Disclosure of portfolio holdings

The UBS U.S. Small Cap Growth Fund will generally post on its website at http://www.ubs.com/us/en/
asset_management/individual_investors/mutual_fund.html, the ten largest equity portfolio holdings of the Fund, and the percentage that each of these holdings represents of the Fund's total assets, as of the most recent calendar quarter-end, 25 calendar days after the end of the calendar quarter.

Each Fund will file its complete schedule of portfolio holdings with the SEC for the first and third quarters of each fiscal year on Form N-PORT. The schedule of portfolio holdings in the Funds' Forms N-PORT are available on the SEC's website at www.sec.gov. Additionally, you may obtain copies of Forms N-PORT from the Funds upon request by calling 1-800-647 1568.

Each Fund's complete schedule of portfolio holdings for the second and fourth quarters of each fiscal year is filed with the SEC on Form N-CSR and appears in the semiannual and annual reports, respectively, sent to shareholders. The semiannual and annual reports for each Fund will be posted on the Funds' website at http://www.ubs.com/us/en/asset_management/
individual_investors/mutual_fund.html. Other information regarding each Fund may also be found on the Fund's website. Please consult the Funds' SAI for a description of the policies and procedures that govern disclosure of the Funds' portfolio holdings.

Dividends and taxes

Dividends and distributions

Each Fund intends to qualify each year as a regulated investment company under the Internal Revenue Code of 1986, as amended ("IRC"). As a regulated investment company, a Fund generally pays no federal income tax on the income and gains it distributes to you. The

UBS U.S. Small Cap Growth Fund expects to declare and distribute all of its net investment income, if any, to shareholders as dividends annually. The UBS Multi Income Bond Fund expects to declare and distribute all of its net investment income, if any, to shareholders as dividends monthly. Each Fund will distribute net realized capital gains, if any, at least annually, usually in December. A Fund may distribute such income dividends and capital gains more frequently, if necessary, in order to reduce or eliminate federal excise or income taxes on the Fund. The amount of any distribution will vary, and there is no guarantee a Fund will pay either an income dividend or a capital gains distribution.

Classes with higher expenses are expected to have lower income dividends.

You will receive income dividends and capital gain distributions in additional shares of the same class of a Fund unless you notify your investment professional or the Fund in writing that you elect to receive them in cash. Clients who own Fund shares through certain wrap fee programs may not have the option of electing to receive dividends in cash. Distribution options may be changed at any time by requesting a change in writing. Dividends and distributions are reinvested on the reinvestment date at the net asset value determined at the close of business on that date.

Annual statements—Each year, the Funds will send you an annual statement (Form 1099) of your account activity to assist you in completing your federal, state and local tax returns. Distributions declared in December to shareholders of record in such month, but paid in January, are taxable as if they were paid in December.

Prior to issuing your statement, the Funds make every effort to reduce the number of corrected forms mailed to you. However, if a Fund finds it necessary to reclassify its distributions or adjust the cost basis of any covered shares (defined below) sold or exchanged after you receive your tax statement, the Fund will send you a corrected Form 1099.

Avoid "buying a dividend"—At the time you purchase your Fund shares, a Fund's net asset value may reflect undistributed income, undistributed capital gains, or net unrealized appreciation in value of portfolio securities held by the Fund. For taxable investors, a subsequent distribution to you of such amounts, although constituting a return of your investment, would be taxable.

Buying shares in a Fund just before it declares an income dividend or capital gains distribution is sometimes known as "buying a dividend."

Taxes

Fund distributions—Each Fund expects, based on investment objective and strategies, that its distributions, if any, will be taxable as ordinary income, capital gains, or some combination of both, unless you are investing through a tax-advantaged arrangement, such as a 401(k) plan or individual retirement account, in which case your distributions may be taxed as ordinary income when withdrawn from the tax-advantaged account. This is true whether you reinvest your distributions in additional Fund shares or receive them in cash.

For federal income tax purposes, Fund distributions of short-term capital gains are taxable to you as ordinary income. Fund distributions of long-term capital gains are taxable to you as long-term capital gains no matter how long you have owned your shares. A portion of income dividends reported by a Fund may be qualified dividend income eligible for taxation by individual shareholders at long-term capital gain rates, provided certain holding period requirements are met. Because the income of the UBS Multi Income Bond Fund is derived from investments earning interest rather than dividend income, generally none or only a small portion of the income dividends paid to you by the Fund is anticipated to be qualified dividend income eligible for taxation by individuals at long-term capital gain tax rates.

The use of derivatives by a Fund may cause the Fund to realize higher amounts of ordinary income or short-term capital gain, distributions of which are taxable to individual shareholders at ordinary income tax rates rather than at the more favorable tax rates for long-term capital gain. Additionally, other rules applicable to derivatives may accelerate the recognition of income or gains to a Fund, defer losses to a Fund, and cause adjustments in the holding periods of a Fund's securities. These rules, therefore, could affect the amount, timing and/or character of distributions to shareholders, and may limit the Fund from using certain types of derivative instruments as part of its investment strategy.

If a Fund qualifies to pass through to you the tax benefits from foreign taxes it pays on its investments, and elects to do so, then any foreign taxes it pays on these investments may be passed through to you as a foreign

tax credit. You will then be required to include your pro-rata share of these taxes in gross income, even though not actually received by you, and will be entitled either to deduct your share of these taxes in computing your taxable income, or to claim a foreign tax credit for these taxes against your U.S. federal income tax.

Sale or redemption of Fund shares—If you are a taxable investor, when you sell or redeem your shares in a Fund, you may realize a capital gain or loss. For tax purposes, an exchange of your Fund shares for shares of a different Family Fund is the same as a sale. Any loss incurred on the sale or exchange of Fund shares held for six months or less will be treated as a long-term capital loss to the extent of capital gain distributions received with respect to such shares. The Funds are required to report to you and the Internal Revenue Service ("IRS") annually on Form 1099-B not only the gross proceeds of Fund shares you sell or redeem but also the cost basis. Cost basis will be calculated using a Fund's default method of average cost, unless you instruct a Fund to use a different calculation method. Shareholders should carefully review the cost basis information provided by the Funds and make any additional basis, holding period or other adjustments that are required when reporting these amounts on their federal income tax returns. If your account is held by your investment representative (financial advisor or other broker), please contact that representative with respect to reporting of cost basis and available elections for your account. Their default method for cost basis reporting may be different than the Funds' default method. Tax-advantaged retirement accounts will not be affected.

Medicare tax—An additional 3.8% Medicare tax is imposed on certain net investment income (including ordinary dividends and capital gain distributions received from a Fund and net gains from redemptions or other taxable dispositions of Fund shares) of US individuals, estates and trusts to the extent that such person's "modified adjusted gross income" (in the case of an individual) or "adjusted gross income" (in the case of an estate or trust) exceeds a threshold amount. This Medicare tax, if applicable, is reported by you on, and paid with, your federal income tax return.

Backup withholding—By law, if you do not provide a Fund with your proper taxpayer identification number and certain required certifications, you may be subject to backup withholding on any distributions of income,

UBS Multi Income Bond Fund

The table below sets forth financial data for one share of beneficial interest outstanding throughout each period presented.

	Class P
	Six months ended December 31, 2021			Years ended June 30,
	(unaudited)			2021			2020			2019			2018			2017
Net asset value, beginning of period	$	15.67		$	15.65		$	15.10		$	14.41		$	14.94		$	15.14
Net investment income (loss)¹		0.15			0.34			0.45			0.49			0.49			0.37
Net realized and unrealized gain (loss)		(0.21	)		(0.02	)		0.50			0.64			(0.63	)		(0.18	)
Net increase (decrease) from operations		(0.06	)		0.32			0.95			1.13			(0.14	)		0.19
Dividends from net investment income		(0.14	)		(0.30	)		(0.40	)		(0.44	)		(0.39	)		(0.39	)
Return of capital		—			—			—			—			—			(0.00	)²
Total dividends and distributions		(0.14	)		(0.30	)		(0.40	)		(0.44	)		(0.39	)		(0.39	)
Net asset value, end of period	$	15.47		$	15.67		$	15.65		$	15.10		$	14.41		$	14.94
Total investment return³		(0.41	)%		2.07	%		6.40	%		7.95	%		(0.88	)%		1.32	%
Ratios to average net assets:
Expenses before fee waivers and/or expense reimbursements		1.44	%⁴		1.52	%		1.38	%⁵		1.45	%⁵		1.30	%		1.29	%
Expenses after fee waivers and/or expense reimbursements		0.50	%⁴		0.50	%		0.50	%⁵		0.50	%⁵		0.50	%		0.50	%
Net investment income (loss)		1.89	%⁴		2.15	%		2.92	%		3.35	%		3.29	%		2.45	%
Supplemental data:
Net assets, end of period (000's)	$	32,756		$	34,629		$	37,048		$	38,949		$	41,245		$	49,919
Portfolio turnover		92	%		169	%		209	%		234	%		236	%		700	%

UBS U.S. Small Cap Growth Fund

The table below sets forth financial data for one share of beneficial interest outstanding throughout each period presented.

	Class P
	Six months ended December 31, 2021			Years ended June 30,
	(unaudited)			2021			2020			2019			2018			2017
Net asset value, beginning of period	$	32.44		$	22.37		$	21.84		$	22.89		$	22.92		$	19.05
Net investment income (loss)¹		(0.06	)		(0.22	)		(0.08	)		(0.06	)		(0.13	)		(0.11	)
Net realized and unrealized gain (loss)		(1.26	)		13.51			2.04			0.96			5.37			4.66
Net increase (decrease) from operations		(1.32	)		13.29			1.96			0.90			5.24			4.55
Dividends from net investment income		(0.06	)		—			—			—			—			—
Distributions from net realized gains		(5.62	)		(3.22	)		(1.43	)		(1.95	)		(5.27	)		(0.68	)
Total dividends and distributions		(5.68	)		(3.22	)		(1.43	)		(1.95	)		(5.27	)		(0.68	)
Net asset value, end of period	$	25.44		$	32.44		$	22.37		$	21.84		$	22.89		$	22.92
Total investment return²		(2.68	)%		60.29	%		9.62	%		6.24	%		26.50	%		24.09	%
Ratios to average net assets:
Expenses before fee waivers and/or expense reimbursements		1.15	%³		1.16	%		1.29	%⁴		1.30	%		1.34	%		1.22	%
Expenses after fee waivers and/or expense reimbursements		0.99	%³		0.99	%		0.99	%⁴		0.99	%		0.99	%		0.99	%
Net investment income (loss)		(0.35	)%³		(0.74	)%		(0.37	)%		(0.27	)%		(0.58	)%		(0.50	)%
Supplemental data:
Net assets, end of period (000's)	$	159,307		$	178,971		$	92,754		$	96,485		$	88,845		$	75,770
Portfolio turnover		18	%		63	%		79	%		54	%		67	%		50	%

Funds' privacy notice

This notice describes the privacy policy of the UBS Family of Funds, the PACE Funds and other mutual funds managed by UBS Asset Management (collectively, the "Funds"). The Funds are committed to protecting the personal information that they collect about individuals who are prospective, current or former investors.

The Funds collect personal information in order to process requests and transactions and to provide customer service. Personal information, which is obtained from applications and other forms or correspondence submitted to the Funds, may include name(s), address, e-mail address, telephone number, date of birth, social security number or other tax identification number, bank account information, information about your transactions and experiences with the Funds, and any affiliation a client has with UBS Financial Services Inc. or its affiliates ("Personal Information").

The Funds limit access to Personal Information to those individuals who need to know that information in order to process transactions and service accounts. These individuals are required to maintain and protect the confidentiality of Personal Information and to follow established procedures. The Funds maintain physical, electronic and procedural safeguards to protect Personal Information and to comply with applicable laws and regulations.

The Funds may share Personal Information with their affiliates to facilitate the servicing of accounts and for other business purposes, or as otherwise required or permitted by applicable law. The Funds may also share Personal Information with non-affiliated third parties that perform services for the Funds, such as vendors that provide data or transaction processing, computer software maintenance and development, and other administrative services. When the Funds share Personal Information with a non-affiliated third party, they will do so pursuant to a contract that includes provisions designed to ensure that the third party will uphold and maintain privacy standards when handling Personal Information. In addition to sharing information with non-affiliated third parties to facilitate the servicing of accounts and for other business purposes, the Funds may disclose Personal Information to non-affiliated third parties as otherwise required or permitted by applicable law. For example, the Funds may disclose Personal Information to credit bureaus or regulatory authorities to facilitate or comply with investigations; to protect against or prevent actual or potential fraud, unauthorized transactions, claims or other liabilities; or to respond to judicial or legal process, such as subpoena requests.

Except as described in this privacy notice, the Funds will not use Personal Information for any other purpose unless the Funds describe how such Personal Information will be used and clients are given an opportunity to decline approval of such use of Personal Information relating to them (or affirmatively approve the use of Personal Information, if required by applicable law). The Funds endeavor to keep their customer files complete and accurate. The Funds should be notified if any Personal Information needs to be corrected or updated. Please call 1-800-647 1568 with any questions or concerns regarding your Personal Information or this privacy notice.

This privacy notice is not a part of the prospectus.