Pioneer Global Equity Fund

Class A Shares (GLOSX)	Class B Shares (GBSLX)	Class C Shares (GCSLX)
Class Y Shares (PGSYX)

Summary ProspectusDecember 31, 2012

Before you invest, you may want to review the fund’s prospectus, which contains 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://us.pioneerinvestments.com/misc/prospectus.jsp. You also can obtain this information at no cost by calling 1-800-225-6292 or by sending an email request to askpioneer@pioneerinvestments.com. The fund’s current prospectus and statement of additional information, dated December 31, 2012, and the independent registered public accounting firm’s report and financial statements in the fund’s annual report to shareholders dated August 31, 2012, are incorporated by reference into this summary prospectus.

Investment objective

Long-term capital growth.

Fees and expenses of the fund

This table describes the fees and expenses that you may pay if you buy and hold shares of the fund.

You may qualify for sales charge discounts if you or your family invest, or agree to invest in the future, at least $50,000 in Class A shares of the Pioneer funds. More information about these and other discounts is available from your investment professional and in the “Sales charges” section of the prospectus beginning on page 29 and the “Sales charges” section of the statement of additional information beginning on page 51.

Summary Prospectus

Shareowner fees
(fees paid directly from your investment)	Class A	Class B	Class C	Class Y
Maximum sales charge (load) when you buy shares (as a percentage of offering price)	5.75%	None	None	None
Maximum deferred sales charge (load) (as a percentage of offering price or the amount you receive when you sell shares, whichever is less)	None	4%	1%	None

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	0.75%	0.75%	0.75%	0.75%
Distribution and Service (12b-1) Fees	0.25%	1.00%	1.00%	0.00%
Other Expenses	0.72%	1.39%	0.78%	0.22%
Acquired Fund Fees and Expenses¹	0.00%	0.00%	0.00%	0.00%
Total Annual Fund Operating Expenses	1.72%	3.14%	2.53%	0.97%
Less: Fee Waiver and Expense Reimbursement²	-0.42%	-0.94%	-0.33%	-0.17%
Net Expenses²	1.30%	2.20%	2.20%	0.80%

Total annual fund operating expenses in the table, before and after fee waiver and expense reimbursements, may be higher than the corresponding ratio of expenses to average net assets shown in the “Financial Highlights” section which does not include acquired fund fees and expenses.

The fund’s investment adviser has contractually agreed to limit ordinary operating expenses (ordinary operating expenses means all fund expenses other than extraordinary expenses, such as litigation, taxes and brokerage commissions) to the extent required to reduce fund expenses to 1.30%, 2.20%, 2.20% and 0.80% of the average daily net assets attributable to Class A, Class B, Class C and Class Y shares, respectively. Acquired fund fees and expenses are not included in the expense limitations noted above. These expense limitations are in effect through January 1, 2014. While in effect, the arrangement may be terminated for a class only by agreement of the adviser and the Board of Trustees.

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 shown and then, except as indicated, redeem all of your shares at the end of those periods. It also assumes that (a) your investment has a 5% return each year and (b) the fund's total annual operating expenses remain the

same except for year one (which considers the effect of the expense limitation). Although your actual costs may be higher or lower, based on these assumptions your costs would be:

	If you redeem your shares				If you do not redeem your shares
	Number of years you own your shares
	1	3	5	10	1	3	5	10
Class A	$700	$1,047	$1,418	$2,456	$700	$1,047	$1,418	$2,456
Class B	623	1,181	1,663	3,051	223	881	1,563	3,051
Class C	323	756	1,316	2,841	223	756	1,316	2,841
Class Y	82	292	520	1,174	82	292	520	1,174

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 152% of the average value of its portfolio.

Principal investment strategies

Normally, the fund invests at least 80% of its net assets (plus the amount of borrowings, if any, for investment purposes) in equity securities of issuers located throughout the world. The fund’s principal focus is on companies that exhibit solid fundamental characteristics and are underappreciated by the market. The fund may invest in securities of any market capitalization, and in securities in any industry or market sector. The fund may invest in both developed and emerging markets without limit. Normally, the fund invests at least 40% of its net assets in issuers located outside of the United States. The fund may invest in equity securities of any market capitalization.

The fund may invest up to 20% of its total assets in debt securities of corporate and government issuers, including up to 5% of its net assets in below investment grade debt securities (known as “junk bonds”), and cash and cash equivalents.

The fund may, but is not required to, use derivatives, including forward foreign currency exchange contracts and futures on equity-based volatility indices. The fund may use derivatives for a variety of purposes, including as

Summary Prospectus

a hedge against adverse changes in the market price of securities, interest rates or currency exchange rates; as a substitute for purchasing or selling securities; and to increase the fund's return as a non-hedging strategy that may be considered speculative. The fund may choose not to make use of derivatives for a variety of reasons, and any use may be limited by applicable law and regulations.

The fund uses a “growth at a reasonable price” style of management. The fund seeks to invest in issuers with above average potential for earnings and revenue growth that are also trading at attractive market valuations. To select stocks, the fund’s investment adviser employs fundamental research and an evaluation of the issuer based on its financial statements and operations. The adviser relies on the knowledge, experience and judgment of its staff and the staff of its affiliates who have access to a wide variety of research. The adviser focuses on the quality and price of individual issuers and securities, not on economic sector or market-timing strategies. The adviser generally sells a portfolio security when it believes that the issuer no longer offers the potential for above average earnings and revenue growth. The adviser makes that determination based upon the same criteria it uses to select portfolio securities.

Principal risks of investing in the fund

You could lose money on your investment in the fund. As with any mutual fund, there is no guarantee that the fund will achieve its objective.

Market risk. The values of securities held by the fund may go up or down, sometimes rapidly or unpredictably, due to general market conditions, such as real or perceived adverse economic, political, or regulatory conditions, inflation, changes in interest or currency rates or adverse investor sentiment. Adverse market conditions may be prolonged and may not have the same impact on all types of securities. The values of securities may fall due to factors affecting a particular issuer, industry or the securities market as a whole. The stock market may perform poorly relative to other investments (this risk may be greater in the short term). The financial crisis that began in 2008 has caused a significant decline in the value and liquidity of many securities of issuers worldwide. Some governmental and non-governmental issuers (notably in Europe) have defaulted on, or been forced to restructure, their debts, and many other issuers have faced difficulties obtaining credit. These market conditions may continue, worsen or spread, including in the U.S., Europe and beyond. Further defaults or restructurings by governments and others of their debt could have

additional adverse effects on economies, financial markets and asset valuations around the world. In response to the crisis, the U.S. and other governments and the Federal Reserve and certain foreign central banks have taken steps to support financial markets. The withdrawal of this support, failure of efforts in response to the crisis, or investor perception that these efforts are not succeeding could negatively affect financial markets generally as well as the value and liquidity of certain securities. Whether or not the fund invests in securities of issuers located in or with significant exposure to countries experiencing economic and financial difficulties, the value and liquidity of the fund’s investments may be negatively affected by the countries experiencing these difficulties. In addition, legislation recently enacted in the U.S. is changing many aspects of financial regulation. The impact of the legislation on the markets, and the practical implications for market participants, may not be fully known for some time. The fund may experience a substantial or complete loss on any individual security.

Risks of non-U.S. investments. Investing in non-U.S. issuers or issuers with significant exposure to foreign markets may involve unique risks compared to investing in securities of U.S. issuers. These risks are more pronounced for issuers in emerging markets or to the extent that the fund invests significantly in one region or country. These risks may include different financial reporting practices and regulatory standards, less liquid trading markets, extreme price volatility, currency risks, changes in economic, political, regulatory and social conditions, sustained economic downturns, financial instability, tax burdens, and investment and repatriation restrictions. Lack of information and less market regulation also may affect the value of these securities. Withholding and other non-U.S. taxes may decrease the fund’s return. Non-U.S. issuers may be located in parts of the world that have historically been prone to natural disasters.

Currency risk. Because the fund may invest in non-U.S. currencies, securities denominated in non-U.S. currencies, and other currency-related investments, the fund is subject to currency risk, meaning that the fund could experience losses based on changes in the exchange rate between non-U.S. currencies and the U.S. dollar. Currency exchange rates can be volatile, and are affected by factors such as general economic conditions, the actions of the U.S. and foreign governments or central banks, the imposition of currency controls and speculation.

Summary Prospectus

Forward foreign currency transactions risk. To the extent that the fund enters into forward foreign currency transactions, it may not fully benefit from or may lose money on the transactions if changes in currency rates do not occur as anticipated or do not correspond accurately to changes in the value of the fund's holdings, or if the counterparty defaults. Such transactions may also prevent the fund from realizing profits on favorable movements in exchange rates. Risk of counterparty default is greater for counterparties located in emerging markets. The fund's ability to use forward foreign currency transactions successfully depends on a number of factors, including the forward foreign currency transactions being available at prices that are not too costly, the availability of liquid markets, and the adviser’s judgment regarding the direction of changes in currency exchange rates.

Style risk. The adviser’s investment style may fall out of favor with investors or produce results that underperform the overall equity market.

Portfolio selection risk. The adviser's judgment about a particular security or issuer, or about the economy or a particular sector, region or market segment, or about an investment strategy, may prove to be incorrect.

Small and mid-size companies risk. Compared to large companies, small- and mid-size companies, and the market for their equity securities, may be more sensitive to changes in earnings results and investor expectations, have more limited product lines and capital resources, experience sharper swings in market values, have limited liquidity, be harder to value or to sell at the times and prices the adviser thinks appropriate, and offer greater potential for gain and loss.

Risks of initial public offerings. Companies involved in initial public offering (IPOs) generally have limited operating histories, and prospects for future profitability are uncertain. The market for IPO issuers has been volatile, and share prices of newly public companies have fluctuated significantly over short periods of time. Further, stocks of newly-public companies may decline shortly after the IPO. There is no assurance that the fund will have access to IPOs. The purchase of IPO shares may involve high transaction costs.

Debt securities risk. Factors that could contribute to a decline in the market value of debt securities in the fund include rising interest rates, if the issuer or other obligor of a security held by the fund fails to pay

principal and/or interest, otherwise defaults or has its credit rating downgraded or is perceived to be less creditworthy or the credit quality or value of any underlying assets declines. Junk bonds involve greater risk of loss, are subject to greater price volatility and are less liquid, especially during periods of economic uncertainty or change, than higher quality debt securities; they may also be more difficult to value. Junk bonds have a higher risk of default or are already in default and are considered speculative.

Market segment risk. To the extent the fund emphasizes, from time to time, investments in a market segment, the fund will be subject to a greater degree to the risks particular to that segment, and may experience greater market fluctuation than a fund without the same focus.

Derivatives risk. Using derivatives can increase fund losses and reduce opportunities for gains when market prices, interest rates or the derivative instruments themselves behave in a way not anticipated by the fund. Using derivatives may increase the volatility of the fund's net asset value and may not provide the result intended. Derivatives may have a leveraging effect on the fund. Some derivatives have the potential for unlimited loss, regardless of the size of the fund’s initial investment. Changes in a derivative’s value may not correlate well with the referenced asset or metric. The fund also may have to sell assets at inopportune times to satisfy its obligations. Derivatives may be difficult to sell, unwind or value, and the counterparty may default on its obligations to the fund. Recent legislation calls for new regulation of the derivatives markets. The extent and impact of the regulation is not yet fully known and may not be for some time. New regulation of derivatives may make them more costly, may limit their availability, or may otherwise adversely affect their value or performance.

Leveraging risk. The value of your investment may be more volatile and other risks tend to be compounded if the fund borrows or uses derivatives or other investments, such as ETFs, that have embedded leverage. Leverage generally magnifies the effect of any increase or decrease in the value of the fund's underlying assets or creates investment risk with respect to a larger pool of assets than the fund would otherwise have, potentially resulting in the loss of all assets. Engaging in such transactions may cause the fund to liquidate positions when it may not be advantageous to do so to satisfy its obligations or meet segregation requirements.

Summary Prospectus

Portfolio turnover risk. If the fund does a lot of trading, it may incur additional operating expenses, which would reduce performance and could cause shareholders to incur a higher level of taxable income or capital gains.

Expense risk. Your actual costs of investing in the fund may be higher than the expenses shown in “Annual fund operating expenses” for a variety of reasons. For example, expense ratios may be higher than those shown if overall net assets decrease. Net assets are more likely to decrease and fund expense ratios are more likely to increase when markets are volatile.

Please note that there are many other factors that could adversely affect your investment and that could prevent the fund from achieving its goals.

An investment in the fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

The fund's past performance

The bar chart and table indicate the risks and volatility of an investment in the fund by showing how the fund has performed in the past. The bar chart shows changes in the performance of the fund's Class A shares from calendar year to calendar year. The table shows the average annual total returns for each class of the fund over time and compares these returns to the returns of the Morgan Stanley Capital International (MSCI) World Index, a broad-based measure of market performance that has characteristics relevant to the fund’s investment strategies. You can obtain updated performance information by visiting https://us.pioneerinvestments.com/performance or by calling 1-800-225-6292.

The fund's past performance (before and after taxes) does not necessarily indicate how it will perform in the future.

The bar chart does not reflect any sales charge you may pay when you buy fund shares. If this amount was reflected, returns would be less than those shown.

Annual return Class A shares (%)

(Year ended December 31)

For the period covered by the bar chart:

The highest calendar quarterly return was 16.82% (07/01/2009 to 09/30/2009).
The lowest calendar quarterly return was –19.26% (10/01/2008 to 12/31/2008).

At September 30, 2012, the year-to-date return was 11.30%.

Average annual total return (%)

(for periods ended December 31, 2011)

	1 Year	5 Years	Since Inception	Inception Date
Class A				12/15/05
Return before taxes	-13.45	-4.47	-0.50
Return after taxes on distributions	-13.89	-4.92	-0.99
Return after taxes on distributions and sale of shares	-8.75	-3.83	-0.54
Class B	-12.51	-4.18	-0.42	12/15/05
Class C	-9.00	-4.18	-0.42	12/15/05
Class Y	-7.65	N/A	8.63	12/31/08
Morgan Stanley Capital International (MSCI) World Index (reflects no deduction for fees, expenses or taxes)	-5.54	-2.37	0.97	12/15/05

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 the investor's tax situation and

Summary Prospectus

may differ from those shown. 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 are shown only for Class A shares. After-tax returns for Class B, Class C and Class Y shares will vary.

Management

Investment adviser	Pioneer Investment Management, Inc.
Portfolio management	Marco Pirondini, Head of Equities, U.S. of Pioneer (portfolio manager of the fund since 2010) and David Glazer, Vice President of Pioneer (portfolio manager of the fund since December 2012)

Purchase and sale of fund shares

You may purchase, exchange or sell (redeem) shares each day the New York Stock Exchange is open through your financial intermediary or, for accounts held directly with the fund, by contacting the fund’s transfer agent in writing or by telephone (Pioneer Investment Management Shareholder Services, Inc., P.O. Box 55014, Boston, MA 02205-5014, tel. 1-800-225-6292).

Your initial investment for Class A or Class C shares must be at least $1,000. Additional investments must be at least $100 for Class A shares and $500 for Class C shares. The initial investment for Class Y shares must be at least $5 million. This amount may be invested in one or more of the Pioneer mutual funds that currently offer Class Y shares. There is no minimum additional investment amount for Class Y shares. Effective December 31, 2009, Class B shares are no longer offered to new or existing shareholders, except for reinvestment of dividends and/or capital gains distributions and exchanges for Class B shares of other Pioneer funds.

Tax information

The fund intends to make distributions that may be taxed as ordinary income or capital gains.

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 salesperson or investment professional to recommend the fund over another investment. Ask your salesperson or investment professional or visit your financial intermediary’s website for more information.

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