Class A & Y Prospectus | PACE® Small/Medium Co Growth Equity Investments

PACE® Small/Medium Co Growth Equity Investments

Investment objective

Capital appreciation.

Fees and expenses of the fund

These tables describe the fees and expenses that you may pay if you buy and hold shares of the fund. You may qualify for sales charge discounts on purchases of Class A shares if you or your family invest, or agree to invest in the future, at least $50,000 in the UBS family of funds. 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 121 of the prospectus and in "Reduced sales charges, additional purchase, exchange and redemption information and other services" on page 219 of the fund's Statement of Additional Information. Different intermediaries and financial professionals may make available different sales charge waivers or discounts. These variations are described in Appendix A on page A-1 of this prospectus (Intermediary-Specific Sales Charge Waivers and Discounts).

Shareholder fees (fees paid directly from your investment)

Shareholder Fees - Class A & Y Prospectus - PACE® Small/Medium Co Growth Equity Investments - USD ($)	CLASS A	CLASS Y
Maximum front-end sales charge (load) imposed on purchases (as a % of the offering price)	5.50%	none
Maximum deferred sales charge (load) (as a % of the lesser of the offering price or the redemption price)	none	none
Exchange fee	none	none

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

Annual Fund Operating Expenses - Class A & Y Prospectus - PACE® Small/Medium Co Growth Equity Investments		CLASS A	CLASS Y
Management fees		0.70%	0.70%
Distribution and/or service (12b-1) fees		0.25%	none
Other expenses (includes administration fee of 0.10%)	[1]	0.25%
Total annual fund operating expenses		1.20%	0.70%

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 redeem 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.

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

Expense Example - Class A & Y Prospectus - PACE® Small/Medium Co Growth Equity Investments - USD ($)	1 year	3 years	5 years	10 years
CLASS A	666	910	1,173	1,925
CLASS Y	72	224	390	871

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 99% of the average value of its portfolio.

Principal strategies

Principal investments

The fund invests primarily in stocks of "emerging growth" companies that are believed to have potential for high future earnings growth relative to the overall market. Under normal circumstances, the fund invests at least 80% of its net assets (plus the amount of any borrowing for investment purposes) in equity securities issued by small/medium capitalization companies. Small/medium capitalization companies means companies with a total market capitalization within the market capitalization range of the companies in the Russell 2500^® Growth Index at the time of purchase. Dividend income is an incidental consideration in the investment advisors' selection of stocks for the fund.

The fund may from time to time invest a significant portion of its assets in the stocks of companies in various economic sectors, such as technology. The fund may invest, to a limited extent, in stocks of companies with larger total market capitalizations and other securities, including securities convertible into stocks. The fund may invest up to 10% of its total assets in non-US securities, which may trade either within or outside the US.

Management process

The fund employs a "manager of managers" structure. UBS Asset Management (Americas) Inc. ("UBS AM"), the fund's manager and primary provider of investment advisory services, has the ultimate authority, subject to oversight by the fund's board, to oversee the fund's subadvisor(s) and recommend their hiring, termination and replacement, and to allocate assets among the fund's subadvisor(s). The relative value of each subadvisor's share of the fund's assets may change over time.

UBS AM's investment process begins with subadvisor selection. UBS AM's portfolio management team constructs a list of potential subadvisors based on information primarily from internal sources and the team's collective knowledge of the industry, but also supplemented by external sources. The team then focuses its research on that list to identify a small number of the most attractive candidates. This research includes analyzing the portfolio holdings and/or positioning of a subadvisor's investment strategy to understand whether the allocation of risk and the drivers of alpha are consistent with the subadvisor's investment philosophy and stated strengths. The most attractive sub-set of those subadvisors is then selected for in-depth, on-site due diligence meetings with representatives from the investment, operations and compliance groups within UBS AM. The due diligence information is then synthesized to select the most attractive candidate(s) for the fund, subject to the board's approval.

In managing the fund and overseeing the fund's subadvisor(s), UBS AM views its research process as an ongoing one, as the team continually seeks to confirm a subadvisor's investment thesis over the appropriate investment horizon. In general, UBS AM leverages its research and market knowledge to construct funds with exposure to various subadvisors that are expected, in combination, to produce the desired overall fund characteristics. UBS AM's ongoing monitoring and risk management process incorporates daily, weekly, monthly, quarterly and annual responsibilities designed to monitor the drivers of fund risk and performance at the subadvisor level and at the overall fund level. Through this process, UBS AM may adjust a fund's positioning by altering its allocation weights across subadvisors within the fund and/or by changing the specific subadvisors within the fund.

The main strategies of the subadvisors include:

•  A growth strategy that focuses on companies viewed as building their earnings power and intrinsic value.

•  A growth strategy that involves seeking to achieve competitive returns in small/medium capitalization companies by identifying unrecognized growth potential.

•  A strategy in which the subadvisor seeks to identify and exploit the perception gap that exits between a company's business strength and the market's expectation of that strength.

Principal 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. The principal risks presented by an investment in the fund are:

Equity risk: Stocks and other equity securities, and securities convertible into stocks, generally fluctuate in value more than bonds. The fund could lose all of its investment in a company's stock.

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.

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.

Management risk: The risk that the investment strategies, techniques and risk analyses employed by UBS AM and/or a subadvisor may not produce the desired results.

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. Moreover, changing market, economic and political conditions in one country or geographic region could adversely impact market, economic and political conditions in other countries or regions.

Multi-manager risk: The investment styles and strategies of the fund's subadvisors may not complement each other as expected by the fund's manager. The same security may be held by different subadvisors, or may be acquired by one subadvisor while another subadvisor of the fund decides to sell the same security. Subadvisors may have different views on the market causing them to make different investment decisions. For example, a subadvisor may determine that it is appropriate to take a temporary defensive position in short-term cash instruments at a time when another subadvisor deems it appropriate to maintain or increase market exposure. Because each subadvisor independently places trades for the fund, the fund may incur higher brokerage costs than would be the case if the fund only had one subadvisor. In addition, UBS AM may be subject to potential conflicts of interests in allocating fund assets because it pays different fees to the subadvisors which could impact its revenues.

Sector risk: Because the fund may invest a significant portion of its assets in the stocks of companies in particular economic sectors, economic changes adversely affecting such a sector may have more of an impact on the fund's performance than another fund having a broader range of investments.

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 bar chart does not reflect the sales charges of the fund's Class A shares; if it did, the total returns shown would be lower. 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 fund's past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future. This may be particularly true given that other subadvisors were responsible for managing portions of the fund's assets during previous periods. Riverbridge Partners, LLC ("Riverbridge") assumed day-to-day management of a portion of the fund's assets on October 1, 2005. LMCG Investments, LLC ("LMCG") and Timpani Capital Management LLC ("Timpani") each assumed day-to-day management of a separate portion of the fund's assets on November 25, 2013. Updated performance for the fund is available at 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 other classes will vary from the Class A shares' after-tax returns shown.

PACE Small/Medium Co Growth Equity Investments Annual Total Returns of Class A Shares*

*  The returns shown above are for Class A. Previously, the returns were shown for Class C, a class of shares the fund ceased offering on July 12, 2018 and that is no longer offered through this prospectus. Class A has substantially similar annual returns to Class C because Class A is invested in the same portfolio of securities Class C was previously invested in. Class A's returns may differ from Class C's returns to the extent that Class A does not have the same expenses Class C had previously.

Total return January 1 - September 30, 2018: 24.87%
Best quarter during calendar years shown—2Q 2009: 20.68%
Worst quarter during calendar years shown—4Q 2008: (26.32)%

Average annual total returns (figures reflect sales charges) (for the periods ended December 31, 2017)

Average Annual Returns - Class A & Y Prospectus - PACE® Small/Medium Co Growth Equity Investments		Average Annual Returns, 1 Year	Average Annual Returns, 5 Years	Average Annual Returns, 10 Years
CLASS A	[1]	16.28%	10.46%	6.58%
CLASS Y	[1]	23.16%	11.81%	7.36%
After Taxes on Distributions | CLASS A	[1]	14.72%	7.30%	5.01%
After Taxes on Distributions and Sale of Fund Shares | CLASS A	[1]	10.48%	7.56%	4.93%
Russell 2500 Growth Index (Index reflects no deduction for fees, expenses or taxes.)	[1]	24.46%	15.47%	9.62%

[1] "Other expenses" include "Acquired fund fees and expenses," which were less than 0.01% of the average net assets of the fund. 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 fee waiver and/or expense reimbursements" may differ from those presented in the financial highlights.

[1] The returns shown above are for Class A. Previously, the returns were shown for Class C, a class of shares the fund ceased offering on July 12, 2018 and that is no longer offered through this prospectus. Class A has substantially similar annual returns to Class C because Class A is invested in the same portfolio of securities Class C was previously invested in. Class A's returns may differ from Class C's returns to the extent that Class A does not have the same expenses Class C had previously.