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 295% of the average value of its portfolio, including TBA transactions, and 38% of the average value of its portfolio, excluding TBA transactions.

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. “Multi income bond” refers to the Fund’s investments in multiple types of fixed income securities/across multiple fixed income sectors.

Under normal circumstances, the Fund will invest at least 65% 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 35% 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 may invest in “to be announced” or “TBA” securities, which are mortgage-backed securities that usually are traded on a forward commitment basis with an approximate principal amount and no defined maturity date, issued or guaranteed by US government agencies and instrumentalities.

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 40% 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 also invest in equity securities, such as preferred stock. Equity investments may include securities of companies of any capitalization size, however the Fund expects to invest primarily in large and mid-capitalization companies.

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 indices. 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. Derivative instruments that provide investment exposure to investments in the Fund’s 80% investment policy or provide investment exposure to one or more of the market risk factors associated with such securities may be counted towards the Fund’s 80% investment policy.

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.

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. 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’s investment process integrates material sustainability and/or environmental, social and governance (“ESG”) considerations into the research process for portfolio investments and portfolio holdings for which ESG data is available. Therefore, the Advisor does not assess every investment for ESG factors and, when it does, not every ESG factor may be identified or evaluated. ESG integration is driven by taking into account material sustainability and/or ESG risks which could impact investment returns, rather than being driven by specific ethical principles or norms. The analysis of material sustainability and/or 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. This analysis is captured in a qualitative ESG assessment by the Advisor that leverages internal research. The Advisor also accesses quantitative ESG data that combines multiple sources and provides information on ESG risks and opportunities. ESG considerations and weights considered may change over time. The Fund’s portfolio managers may

still invest in securities without respect to sustainability and/or ESG considerations or in securities which present sustainability and/or ESG risks, including where the portfolio managers believe the potential compensation outweighs the risks identified.

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, prior 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. 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 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 www.ubs.com/us/en/assetmanagement/funds/mutual‑fund‑performance.

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 other classes will vary from the Class P shares’ after-tax returns shown.