Share Class: Ticker Symbol

A:BNAAX  B:BNABX  C:BNACX  Y:BNAYX

UBS Dynamic Alpha Fund

Summary Prospectus—October 28, 2010

Before you invest, you may want to review the Fund's prospectus and statement of additional information, which contain more information about the Fund and its risks. You can find the Fund's prospectus, statement of additional information and other information about the Fund online at http://www.ubs.com/1/e/globalam/Americas/globalamus/
globalamusii/mutual_fund.html. You can also get this information at no cost by calling 1-800-647 1568 or by sending an email request to Ubs@fundinsite.com. The current prospectus and statement of additional information, dated October 28, 2010 are incorporated by reference into this summary prospectus (i.e., they are legally a part of this summary prospectus). This summary prospectus offers Class A, Class B, Class C and Class Y shares of the Fund; however, Class B shares of the Fund are only offered to existing shareholders of Class B shares with respect to the reinvestment of dividends and dist ributions and exchanges of Class B shares of the Fund and other series of the UBS Family of Funds.

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 and hold shares of the Fund. You may qualify for a sales charge waiver or discount if you and your family invest, or agree to invest in the future, at least $50,000 in the Fund. More information about these and other discounts and waivers, as well as eligibility requirements for each share class, is available from your financial advisor and in "Managing your fund account" on page 36 of the Fund's prospectus and in "Reduced sales charges, additional purchase, exchange and redemption information and other services" on page 110 of the Fund's statement of additional information.

Shareholder fees (fees paid directly from your investment)

	Class A			Class B			Class C			Class Y
Maximum front-end sales charge (load) imposed on purchases (as a % of offering price)		5.50	%		None			None			None
Maximum contingent deferred sales charge (load) (CDSC) (as a % of purchase or sales price, whichever is less)		None			5.00	%		1.00	%		None
Redemption fee (as a % of amount redeemed within 90 days of purchase, if applicable)		1.00	%		1.00	%		1.00	%		1.00	%

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

	Class A			Class B			Class C			Class Y
Management fees		0.84	%		0.84	%		0.84	%		0.84	%
Distribution and/or service (12b-1) fees		0.25			1.00			1.00			None
Other expenses:
Securities loan fees and dividend expenses for securities sold short(1)		0.57			0.57			0.57			0.58
Other		0.28			0.37			0.29			0.20
Total other expenses		0.85			0.94			0.86			0.78
Acquired fund fees and expenses		0.04			0.04			0.04			0.04
Total annual fund operating expenses(1)		1.98			2.82			2.74			1.66
Management fee waiver/expense reimbursements		0.02			0.11			0.03			0.00
Total annual fund operating expenses after management fee waiver/expense reimbursements(2)(3)		1.96			2.71			2.71			1.66

¹  The "Securities loan fees and dividend expenses for securities sold short" has been restated to reflect the anticipated increase in such expense and fees in light of the Fund's new investment strategy.

²  Since 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" and "Total annual fund operating expenses after management fee waiver/expense reimbursements" will differ from those presented in the Financial highlights.

³  The Trust, with respect to the Fund, and UBS Global Asset Management (Americas) Inc., the Fund's investment advisor ("UBS Global AM (Americas)" or the "Advisor"), have entered into a written agreement pursuant to which the Advisor has agreed to waive a portion of its management fees and/or to reimburse expenses (excluding expenses incurred through investment in other investment companies, interest, taxes, brokerage commissions, extraordinary expenses, securities loan fees and dividend expenses for securities sold short) 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, extraordinary expenses, securities loan fees and

dividend expenses for securities sold short), through the period ending October 27, 2011, do not exceed 1.35% for Class A shares, 2.10% for Class B shares, 2.10% for Class C shares and 1.10% for Class Y shares. Pursuant to the written agreement, the Advisor is entitled to be reimbursed for any fees it waives and expenses it reimburses for a period of three years following such fee waivers and expense reimbursements to the extent that such reimbursement of the Advisor by the Fund will not cause the Fund to exceed any applicable expense limit that is in place for the Fund.

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 A	$	738	$	1,135	$	1,557	$	2,728
Class B (assuming sale of all shares at end of period)		774		1,164		1,679		2,755
Class B (assuming no sale of shares)		274		864		1,479		2,755
Class C (assuming sale of all shares at end of period)		374		847		1,447		3,068
Class C (assuming no sale of shares)		274		847		1,447		3,068
Class Y		169		523		902		1,965

Portfolio turnover

The Fund pays transaction costs, such as commissions, 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 58% of the average value of its portfolio.

Principal strategies

Principal investments

The Fund invests in securities and financial instruments to gain exposure to global equity, global fixed income and cash equivalent markets, including global currencies. The Fund may invest in equity and fixed income securities of issuers located within and outside the United States or in open-end investment companies advised by the Advisor, to gain exposure to certain global equity and global fixed income markets. The Fund is a non-diversified fund.

Investments in fixed income securities may include, but are not limited to, debt securities of governments throughout the world (including the United States), their agencies and instrumentalities, debt securities of corporations and supranationals, inflation protected securities, convertible bonds, mortgage-backed securities, asset-backed securities, equipment trusts and other collateralized debt securities. Investments in fixed income securities may include issuers in both developed (including the United States) and emerging markets. The Fund's fixed income investments may reflect a broad range of investment maturities, credit qualities and sectors, including high yield (lower-rated) securities and convertible debt securities.

Investments in equity securities may include, but are not limited to, common stock and preferred stock of issuers in developed nations (including the United States) and emerging markets. Equity investments may include securities of companies of any capitalization size.

In addition, the Fund attempts to generate positive returns and manage risk through asset allocation and sophisticated currency management techniques. These decisions are integrated with analysis of global market and economic conditions.

The Fund may, but is not required to, use exchange-traded or over-the-counter derivative instruments for risk management purposes or as part of the Fund's investment strategies. The derivatives in which the Fund may invest include options, futures, forward agreements, swap agreements (specifically, interest rate, total return, currency and credit default swaps), credit-linked securities, equity participation notes and equity linked notes. 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 markets, currencies or securities. Opt ions on indices, futures on indices, forward agreements, interest rate swaps, total return swaps, credit default swaps and credit-linked securities may also be used to adjust the Fund's portfolio duration. Any of the derivatives listed above may be used to achieve a negative portfolio duration. The Fund also may sell securities short as part of its investment strategy.

Under certain market conditions, the Fund may invest in companies at the time of their initial public offering ("IPO"). To the extent permitted by the Investment Company Act of 1940, as amended, the Fund may

borrow money from banks to purchase investments for the Fund.

Management process

The Fund is a multi-asset fund. Asset allocation decisions are tactical, based upon the Advisor's assessment of valuations and prevailing market conditions in the United States and abroad. In determining the asset allocation of the Fund, the Advisor may utilize fundamental valuation and market behavior indicators to construct the Fund's portfolio.

With respect to the Advisor's selection of specific equity securities for inclusion in the Fund's equity asset classes, the Advisor may utilize fundamental valuation, growth-oriented and quantitative research strategies.

In selecting equity securities for the Fund using the fundamental valuation process, the Advisor selects securities whose fundamental values (the Advisor's assessment of what a security is worth) it believes are greater than what is reflected in market prices. A stock with a market price below its assessed fundamental value would be considered a long candidate for inclusion in the Fund's portfolio. A stock with a market price above its assessed fundamental value would be considered a short candidate for inclusion in the Fund's portfolio.

Under certain circumstances the Advisor also may utilize growth-oriented strategies within its equity asset classes for a portion of the allocation. In selecting growth equities, the Advisor seeks to invest in companies that possess a dominant market position and franchise, a major technological edge or a unique competitive advantage.

To make investment decisions for certain equity asset classes, the Advisor utilizes quantitative research techniques that identify investment opportunities by systematically exploring many small reappearing market anomalies to provide consistent excess returns for the Fund.

The Advisor's fixed income strategy combines judgments about the absolute value of the fixed income universe and the relative value of issuer sectors, maturity intervals, security durations, credit qualities and coupon segments, as well as specific circumstances facing the issuers of fixed income securities.

In employing its investment strategies for the Fund, the Advisor attempts to achieve a total rate of return for the Fund that meets or exceeds 5% per year on a real (i.e., inflation-adjusted) basis and net of management fees over rolling five year time horizons. The Advisor does not represent or guarantee that the Fund will meet this total return goal.

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 the 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.

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.

High yield bond risk: The risk that the issuer of bonds with ratings of BB (S&P) or Ba (Moody's) or below, or deemed of equivalent quality, will default or otherwise be unable to honor a financial obligation. 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-quality bonds are more likely to be subject to an issuer's default or downgrade than investment grade (higher-quality) bonds.

Government securities risk: There are different types of US government securities with different levels of credit risk, including 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.

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.

Limited 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.

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. 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. In addition, 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.

Asset allocation risk: The risk that the Fund may allocate assets to an asset category that performs poorly relative to other asset categories.

Non-diversification risk: The Fund is a non-diversified investment company, which means that the Fund may invest more of its assets in a smaller number of issuers than a diversified investment company. As a non-diversified fund, the Fund's share price may be more volatile and the Fund has a greater potential to realize losses upon the occurrence of adverse events affecting a particular issuer.

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. When using derivatives for non-hedging purposes, 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 and management risks. 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.< /font>

Short sales risk: There are certain unique risks associated with the use of short sales strategies. When selling a security short, the Advisor will sell a security it does not own at the then-current market price and then borrow the security to deliver to the buyer. The Fund is then obligated to buy the security on a later date so it can return the security to the lender. Short sales therefore involve the risk that the Fund will incur a loss by subsequently buying a security at a higher price than the price at which the Fund previously sold the security short. This would occur if the securities lender required the Fund to deliver the securities the Fund had borrowed at the commencement of the short sale and the Fund was unable to either purchase the security at a favorable price or to borrow the security from another securities lender. If this occurs at a time when other short sellers of the security also want to close out their positions, a "short squeeze" can occur. A short squeeze occurs when demand is greater than supply for the security sold short. Moreover, because a Fund's loss on a short sale arises from increases in the value of the security sold short, such loss, like the price of the security sold short, is theoretically unlimited. By contrast, a Fund's loss on a long position arises from decreases in the value of the security and therefore is limited by the fact that a security's value cannot drop below zero. It is possible that the Fund's securities held long will decline in value at the same time that the value of the securities sold short increases, thereby increasing the potential for loss.

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.

Leverage risk associated with borrowing: The Fund may borrow money from banks to purchase investments for the Fund, which is a form of leverage. If the Fund borrows money to purchase securities and the Fund's investments decrease in value, the Fund's losses will be greater than if the Fund did not borrow money for investment purposes. In addition, if the return on an investment purchased with borrowed funds is not sufficient to cover the cost of borrowing,

then the net income of the Fund would be less than if borrowing were not used.

Investing in other funds risks: The Fund's investment performance is affected by the investment performance of the underlying funds in which the Fund may invest. Through its investment in the underlying funds, the Fund is subject to the risks of the underlying funds' investments and subject to the underlying funds' expenses.

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 performance information that follows shows the Fund's performance information in a bar chart and an average annual total returns table. 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 MSCI World Free Index (net) shows how the Fund's performance compares to an index that is designed to measure the equity market performance of developed markets. The US Consumer Price Index (CPI) shows how the Fund's performance compares to monthly data on changes in the prices paid by urban consumers. Life of class performance for the BofA Merrill Lynch US Treasury 1-5 Year Index, the MSCI World Free Index (net) and the US Consumer Price Index (CPI) is as of the inception month end. Indices reflect no deduction for fees, expenses or taxes, except for the MSCI World Free Index (net) which reflects no deduction for fees and expenses. 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
http://globalam-us.ubs.com/corpweb/performance.do.

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-deferred arrangements, such as 401(k) plans or individual retirement accounts. After-tax returns for other classes will vary from the Class Y shares' after-tax returns shown.

Average annual total returns
(for the periods ended December 31, 2009)

Class (inception date)	1 year			Life of class
Class A (1/27/05)
Return before taxes		20.32	%		1.11	%
Class B (1/27/05)
Return before taxes		21.31			1.22
Class C (1/27/05)
Return before taxes		25.36			1.46
Class Y (1/27/05)
Return before taxes		27.33			2.57
Return after taxes on distributions		25.30			0.79
Return after taxes on distributions and sale of fund shares		17.91			1.80
BofA Merrill Lynch US Treasury 1-5 Year Index		0.23			4.49
MSCI World Free Index (net)		29.99			2.52
US Consumer Price Index (CPI)		2.72			2.56

Investment advisor

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

Portfolio managers

•  Curt Custard, portfolio manager of the Fund since 2008.

•  Andreas Koester, portfolio manager of the Fund since 2009.

•  Jonathan Davies, portfolio manager of the Fund since 2009.

•  Phillip Torres, portfolio manager of the Fund since 2010.

Purchase & sale of Fund shares

You may purchase, redeem or exchange shares of the Fund on any business day, which is any day the New York Stock Exchange is open for business. You may purchase, redeem or exchange shares of the Fund either through a financial advisor or directly from the Fund. In general, the minimum initial investment is $1,000 and the minimum subsequent investment is $100.

Tax information

The dividends and distributions you receive from the Fund are taxable and will generally be taxed as ordinary income, capital gains, or some combination of both, unless you are investing through a tax deferred arrangement, such as a 401(k) plan or an individual retirement account.

Payments to broker/dealers and other financial intermediaries

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund and its related companies may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your financial advisor to recommend the Fund over another investment. Ask your financial advisor or visit your financial intermediary's Web site for more information.

This page intentionally left blank.

©2010 UBS Global Asset Management (Americas) Inc.
UBS Global Asset Management (Americas) Inc.
is a subsidiary of UBS AG.
All rights reserved.
S1209

www.ubs.com/globalam-us