# EDGAR Filing Document

**Accession Number:** 0000863334
**File Stem:** 0000863334-23-000003
**Filing Date:** 2023-2
**Character Count:** 42874
**Document Hash:** 447dc15df8e795daa8a7323e854306c5
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000863334-23-000003.hdr.sgml**: 20230224

**ACCESSION NUMBER**: 0000863334-23-000003

**CONFORMED SUBMISSION TYPE**: 497K

**PUBLIC DOCUMENT COUNT**: 3

**FILED AS OF DATE**: 20230224

**DATE AS OF CHANGE**: 20230224

**EFFECTIVENESS DATE**: 20230224

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** PIONEER MID CAP VALUE FUND
- **CENTRAL INDEX KEY:** 0000863334
- **IRS NUMBER:** 043091159
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1031

**FILING VALUES:**
- **FORM TYPE:** 497K
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 033-34801
- **FILM NUMBER:** 23668038

**BUSINESS ADDRESS:**
- **STREET 1:** 60 STATE ST - 5TH FL
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02109-1820
- **BUSINESS PHONE:** 617-742-7825

**MAIL ADDRESS:**
- **STREET 1:** 60 STATE ST
- **STREET 2:** 5TH FLOOR
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02109-1820

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** PIONEER CAPITAL GROWTH FUND /MA/
- **DATE OF NAME CHANGE:** 19980630

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** PIONEER GROWTH TRUST
- **DATE OF NAME CHANGE:** 19920703

## Series and Classes Contracts Data

### Pioneer Mid Cap Value Fund (Series ID: S000004143)

| Class ID   | Class Name                          | Ticker Symbol   |
|:---|:---|:---|
| C000011629 | Pioneer Mid Cap Value Fund: Class A | PCGRX           |
| C000011631 | Pioneer Mid Cap Value Fund: Class C | PCCGX           |
| C000011632 | Pioneer Mid Cap Value Fund: Class Y | PYCGX           |
| C000011633 | Pioneer Mid Cap Value Fund: Class R | PCMRX           |
| C000156004 | Pioneer Mid Cap Value Fund: Class K | PMCKX           |

**Pioneer Mid Cap Value Fund** 

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| | | | | |
|:---|:---|:---|:---|:---|
| **Class A Shares** | **Class C Shares** | **Class K Shares** | **Class R Shares** | **Class Y Shares** |
| **PCGRX** | **PCCGX** | **PMCKX** | **PCMRX** | **PYCGX** |

---

Summary Prospectus \| March 1, 2023

**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, reports to shareholders, and other information about the fund online at https://www.amundi.com/usinvestors/Resources/Download-Literature. You also can obtain this information at no cost by calling 1-800-225-6292 or by sending an email request to US.AskAmundiUS@amundi.com. The fund's current** [**prospectus and statement of additional**](https://www.sec.gov/ix?doc=/Archives/edgar/data/863334/000119312523048677/d435008d485bpos.htm)[**information**](https://www.sec.gov/ix?doc=/Archives/edgar/data/863334/000119312523048677/d435008d485bpos.htm)**, dated March 1, 2023, and the independent registered public accounting firm's report and** [**financial statements**](https://www.sec.gov/Archives/edgar/data/863334/000182126823000015/pio84859.htm) **in the fund's annual report to shareholders dated October 31, 2022, are incorporated by reference into this summary prospectus.**

![](covers_amundipioneer2.jpg)

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**Summary Prospectus**

**Investment objective**

Capital appreciation by investing in a diversified portfolio of securities consisting primarily of common stocks.

**Fees and expenses of the fund**

This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the fund. **You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below.**

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 48, the "Intermediary defined sales charge waiver policies" section of the prospectus beginning on page 86, and the "Sales charges" section of the statement of additional information beginning on page 55. If you invest in Class K shares or Class Y shares through an investment professional or financial intermediary, that investment professional or financial intermediary may charge you a commission. Such commissions, if any, are not charged by the fund and are not reflected in the fee table or expense example below.

**Shareowner fees** <br>(fees paid directly from your investment)

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| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class A** | **Class C** | **Class K** | **Class R** | **Class Y** |
| Maximum sales charge (load) when you buy shares <br> (as a percentage of offering price)<br>| 5.75% |  |  |  |  |
| Maximum deferred sales charge (load) (as a <br> percentage of offering price or the amount you <br> receive when you sell shares, whichever is less)<br>| None<sup>1</sup> <br>| 1% |  |  |  |

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

---

| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **Class A** | **Class C** | **Class K** | **Class R** | **Class Y** |
| Management Fees | 0.68% | 0.68% | 0.68% | 0.68% | 0.68% |
| Distribution and Service (12b-1) Fees | 0.25% | 1.00% | 0.00% | 0.50% | 0.00% |
| Other Expenses | 0.17% | 0.24% | 0.13% | 0.35% | 0.21% |
| Total Annual Fund Operating Expenses | 1.10% | 1.92% | 0.81% | 1.53% | 0.89% |

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Class A purchases of $500,000 or more that are not subject to an initial sales charge may be subject to a contingent deferred sales charge of 1%. See "Sales charges."

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

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| | | | | | | | | |
|:---|:---|:---|:---|:---|:---|:---|:---|:---|
|  | **If you redeem your shares** | **If you redeem your shares** | **If you redeem your shares** | **If you redeem your shares** | **If you do not redeem your shares** | **If you do not redeem your shares** | **If you do not redeem your shares** | **If you do not redeem your shares** |
|  | **Number of years you own your shares** | **Number of years you own your shares** | **Number of years you own your shares** | **Number of years you own your shares** | **Number of years you own your shares** | **Number of years you own your shares** | **Number of years you own your shares** | **Number of years you own your shares** |
|  | **1** | **3** | **5** | **10** | **1** | **3** | **5** | **10** |
| Class A | $681 | $905 | $1146 | $1838 | $681 | $905 | $1146 | $1838 |
| Class C | 295 | 603 | 1037 | 2243 | 195 | 603 | 1037 | 2243 |
| Class K | 83 | 259 | 450 | 1002 | 83 | 259 | 450 | 1002 |
| Class R | 156 | 483 | 834 | 1824 | 156 | 483 | 834 | 1824 |
| Class Y | 91 | 284 | 493 | 1096 | 91 | 284 | 493 | 1096 |

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**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 67% of the average value of its portfolio.

**Principal investment strategies**

Normally, the fund invests at least 80% of its total assets in equity securities of mid-size companies. Mid-size companies are those with market values, at the time of investment, that do not exceed the greater of the market capitalization of the largest company within the Russell Midcap Value Index ($53 billion as of December 31, 2022) or the 3-year rolling average of the market capitalization of the largest company within the Russell Midcap Value Index ($49.39 billion as of December 31, 2022), as measured at the end of the preceding month, and are not less than the smallest company within the index. The Russell Midcap Value Index measures the performance of U.S. mid-cap value stocks. The size of the companies in the index changes constantly with market conditions and the composition of the index. The equity securities in which the fund principally invests are common stocks, preferred stocks and depositary receipts, but the fund may invest in other

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**Summary Prospectus**

types of equity securities to a lesser extent, such as securities of other investment companies (including mutual funds, exchange-traded funds and closed-end funds) that invest primarily in equity securities, equity interests in real estate investment trusts (REITs), warrants and rights. The fund may invest in initial public offerings of equity securities.

The fund may invest up to 25% of its total assets in securities of non-U.S. issuers. The fund will not invest more than 5% of its total assets in the securities of emerging markets issuers.

The fund may invest up to 20% of its net assets in REITs.

The fund may invest up to 20% of its total assets in debt securities. The fund may invest up to 5% of its net assets in below investment grade debt securities (known as "junk bonds"), including below investment grade convertible debt securities.

The fund may, but is not required to, use derivatives, such as stock index futures and options. The fund may use derivatives for a variety of purposes, including: in an attempt to hedge against adverse changes in the market price of securities, interest rates or currency exchange rates; as a substitute for purchasing or selling securities; to attempt to increase the fund's return as a non-hedging strategy that may be considered speculative; to manage portfolio characteristics; and as a cash flow management technique. 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 may also hold cash or other short-term investments.

The fund uses a "value" style of management. The adviser seeks to identify securities that are selling at reasonable prices or at substantial discounts to their underlying values and then holds these securities until the market values reflect their intrinsic values. The adviser evaluates a security's potential value, including the attractiveness of its market valuation, based on the company's assets and prospects for earnings growth. In making that assessment, the adviser employs fundamental research and an evaluation of the issuer based on its financial statements and operations, employing a bottom-up analytic style, which focuses on specific securities rather than on industries. The adviser focuses on the quality and price of individual issuers and securities. The adviser generally sells a portfolio security when it believes that the security's market value reflects its underlying value.

The adviser integrates environmental, social and corporate governance (ESG) considerations into its investment research process by evaluating the business models and practices of issuers and their ESG-related risks. The 's adviser believes ESG analysis is a meaningful facet of fundamental research, the process of evaluating an issuer based on its financial position, business operations, competitive standing

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and management. This process considers ESG information, where available, in assessing an investment's performance potential. The 's adviser generally considers ESG information in the context of an issuer's respective sector or industry. The 's adviser may consider ESG ratings provided by third parties or internal sources, as well as issuer disclosures and public information, in evaluating issuers. ESG considerations are not a primary focus of the fund, and the weight given by the 's adviser to ESG considerations in making investment decisions will vary and, for any specific decision, they may be given little or no weight. Notwithstanding the foregoing, the 's adviser generally will not invest fund assets in (i) companies that the 's adviser determines have significant involvement in the manufacturing of complete tobacco products, (ii) companies engaged in the production, sale, storage of, or providing services for, certain controversial weapons, including chemical, biological and depleted uranium weapons and certain antipersonnel mines and cluster bombs, or (iii) companies with involvement in the production or sale of nuclear weapons.

**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 market prices of securities or other assets 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, political instability, recessions, inflation, changes in interest or currency rates, lack of liquidity in the markets, the spread of infectious illness or other public health issues, armed conflict, market disruptions caused by tariffs, trade disputes, sanctions or other government actions, or other factors or adverse investor sentiment. If the market prices of the fund's securities and assets fall, the value of your investment will go down. A change in financial condition or other event affecting a single issuer or market may adversely impact securities markets as a whole.

In the past decade, financial markets throughout the world have experienced increased volatility, depressed valuations, decreased liquidity and heightened uncertainty. Governmental and non-governmental issuers have defaulted on, or been forced to restructure, their debts. These conditions may continue, recur, worsen or spread. Events that have contributed to these market conditions include, but are not limited to, major cybersecurity events; geopolitical events (including wars, terror attacks and economic sanctions); measures to address budget deficits; downgrading of sovereign debt; changes in oil and commodity prices; dramatic changes in currency exchange rates; global pandemics; and public sentiment. The fallout from the COVID-19 pandemic and subsequent variants of COVID-19, and

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**Summary Prospectus**

the long-term impact on economies, markets, industries and individual issuers, are not known. Some sectors of the economy and individual issuers have experienced or may experience particularly large losses. Periods of extreme volatility in the financial markets; reduced liquidity of many instruments; and disruptions to supply chains, consumer demand and employee availability, may continue for some time.

Raising the ceiling on U.S. government debt has become increasingly politicized. Any failure to increase the ceiling on U.S. government debt could lead to a default on U.S. government obligations, with unpredictable consequences for economies and markets in the U.S. and elsewhere. Recently, inflation and interest rates have increased and may rise further. These circumstances could adversely affect the value and liquidity of the fund's investments, impair the fund's ability to satisfy redemption requests, and negatively impact the fund's performance. Following Russia's invasion of Ukraine, Russian securities have lost all, or nearly all, their market value. Other securities or markets could be similarly affected by past or future political, geopolitical or other events or conditions.

Governments and central banks, including the U.S. Federal Reserve, have taken extraordinary and unprecedented actions to support local and global economies and the financial markets. These actions have resulted in significant expansion of public debt, including in the U.S. The consequences of high public debt, including its future impact on the economy and securities markets, may not be known for some time. U.S. Federal Reserve or other U.S. or non-U.S. governmental or central bank actions, including increases or decreases in interest rates, or contrary actions by different governments, could negatively affect financial markets generally, increase market volatility and reduce the value and liquidity of securities in which the fund invests. Policy and legislative changes in the U.S. and in other countries are affecting many aspects of financial regulation, and these and other events affecting global markets, such as the United Kingdom's exit from the European Union (or Brexit), potential trade imbalances with China, or other countries, or sanctions or other government actions against Russia, other nations or individuals or companies (or their countermeasures), may contribute to decreased liquidity and increased volatility in the financial markets. The impact of these changes on the markets, and the implications for market participants, may not be fully known for some time.

The United States and other countries are periodically involved in disputes over trade and other matters, which may result in tariffs, investment restrictions and adverse impacts on affected companies and securities. For example, the United States has imposed tariffs and other trade barriers on Chinese exports, has restricted sales of certain categories of goods to China, and has established barriers to investments

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in China. Trade disputes may adversely affect the economies of the United States and its trading partners, as well as companies directly or indirectly affected and financial markets generally. The United States government has prohibited U.S. persons, such as the fund, from investing in Chinese companies designated as related to the Chinese military. These and possible future restrictions could limit the fund's opportunities for investment and require the sale of securities at a loss or make them illiquid. Moreover, the Chinese government is involved in a longstanding dispute with Taiwan that has included threats of invasion. If the political climate between the United States and China does not improve or continues to deteriorate, if China were to attempt unification of Taiwan by force, or if other geopolitical conflicts develop or get worse, economies, markets and individual securities may be severely affected both regionally and globally, and the value of the fund's assets may go down.

Economies and financial markets throughout the world are increasingly interconnected. Economic, financial or political events, trading and tariff arrangements, armed conflict including Russia's military invasion of Ukraine, terrorism, natural disasters, infectious illness or public health issues, cybersecurity events, supply chain disruptions, sanctions against Russia, other nations or individuals or companies and possible countermeasures, and other circumstances in one country or region could have profound impacts on other countries or regions and on global economies or markets. As a result, whether or not the fund invests in securities of issuers located in or with significant exposure to the countries or regions directly affected, the value and liquidity of the fund's investments may be negatively affected. The fund may experience a substantial or complete loss on any security or derivative position.

**Mid-size companies risk.** Compared to large companies, mid-size companies, and the market for their equity securities, may be more sensitive to changes in earnings results and investor expectations, or poor economic or market conditions, including those experienced during a recession, have more limited product lines, operating histories, markets or capital resources, may be dependent upon a limited management group, 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.

**Value style risk.** The prices of securities the adviser believes are undervalued may not appreciate as expected or may go down. Value stocks may fall out of favor with investors and underperform the overall equity market. A value stock may not

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**Summary Prospectus**

increase in price as anticipated by the adviser if other investors fail to recognize the company's value and bid up the price or the factors that the adviser believes will increase the price of the security do not occur or do not have the anticipated effect.

**Portfolio selection risk.** The adviser's judgment about a particular security or issuer, or about the economy or a particular sector, region, market segment or industry, or about an investment strategy, may prove to be incorrect or may not produce the desired results, or there may be imperfections, errors or limitations in the models, tools and information used by the adviser.

**ESG risk.** The fund's adviser may consider ESG information in its investment research process. This may mean forgoing some investment opportunities available to funds that do not consider ESG information. In considering ESG information, the adviser may use third party ESG ratings information that it believes to be reliable, but such information may not be accurate or complete, or may be biased. ESG considerations are not a primary focus of the fund, and the weight given by the adviser to ESG considerations in making investment decisions will vary and, for any specific decision, they may be given little or no weight.

**Risks of non-U.S. investments.** Investing in non-U.S. issuers, or in U.S. issuers that have 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, military conflicts and sanctions, terrorism, sustained economic downturns, financial instability, reduction of government or central bank support, inadequate accounting standards, tariffs, tax disputes or other tax burdens, nationalization or expropriation of assets, arbitrary application of laws and regulations or lack of rule of law, 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. Emerging market economies tend to be less diversified than those of more developed countries. They typically have fewer medical and economic resources than more developed countries and thus they may be less able to control or mitigate the effects of a pandemic. Investing in depositary receipts is subject to many of the same risks as investing directly in non-U.S. issuers. Depositary receipts may involve higher expenses and may trade at a discount (or premium) to the underlying security.

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A number of countries in the European Union (EU) have experienced, and may continue to experience, severe economic and financial difficulties. In addition, the United Kingdom has withdrawn from the EU (commonly known as "Brexit"). The range and potential implications of possible political, regulatory, economic, and market outcomes of Brexit cannot be fully known but could be significant, potentially resulting in increased volatility, illiquidity and potentially lower economic growth in the affected markets, which will adversely affect the fund's investments.

Sanctions or other government actions against certain countries could negatively impact the fund's investments in securities that have exposure to those countries. Circumstances that impact one country could have profound impacts on other countries and on global economies or markets. China and other developing market countries may be subject to considerable degrees of economic, political and social instability. The U.S. government has imposed restrictions on U.S. investor participation in certain Chinese investments. These matters could adversely affect China's economy. In addition, China's long-running conflict over Taiwan's sovereignty, border disputes with many neighbors and historically strained relations with other Asian countries could result in military conflict that could adversely impact the economies of China and other Asian countries, disrupt supply chains, and severely affect global economies and markets.

Russia launched a large-scale invasion of Ukraine on February 24, 2022. In response to the military action by Russia, various countries, including the U.S., the United Kingdom, and European Union, issued broad-ranging economic sanctions against Russia and Belarus and certain companies and individuals. Russia has taken retaliatory actions, including preventing repatriation of capital by U.S. and other investors. Since then, Russian securities have lost all, or nearly all, their market value, and many other issuers, securities and markets have been adversely affected. The ongoing conflict has resulted in significant market disruptions, including in certain markets, industries and sectors, such as the oil and natural gas markets, and negatively affected global supply chains, food supplies, inflation and global growth. The U.S. and other countries may impose sanctions on other countries, companies and individuals in light of Russia's military invasion. The extent and duration of the military action or future escalation of such hostilities, the extent and impact of existing and future sanctions, market disruptions and volatility, and the result of any diplomatic negotiations cannot be predicted. These and any related events could have a significant impact on the value and liquidity of certain fund investments, on fund performance and the value of an investment in the fund.

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**Summary Prospectus**

**Risks of investments in real estate related securities.** Investments in real estate securities are affected by economic conditions, interest rates, governmental actions and other factors. In addition, investing in REITs involves unique risks. They are significantly affected by the market for real estate and are dependent upon management skills and cash flow. REITs may have lower trading volumes and may be subject to more abrupt or erratic price movements than the overall securities markets. Mortgage REITs are particularly subject to interest rate and credit risks. In addition to its own expenses, the fund will indirectly bear its proportionate share of any management and other expenses paid by REITs in which it invests. Many real estate companies, including REITs, utilize leverage.

**Risks of initial public offerings.** Companies involved in initial public offerings (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. The purchase of IPO shares may involve high transaction costs.

**Risks of investment in other funds.** Investing in other investment companies, including exchange-traded funds (ETFs) and closed-end funds, subjects the fund to the risks of investing in the underlying securities or assets held by those funds. When investing in another fund, the fund will bear a pro rata portion of the underlying fund's expenses, including management fees, in addition to its own expenses. ETFs and closed-end funds are bought and sold based on market prices and can trade at a premium or a discount to the ETF's or closed-end fund's net asset value. Such funds may trade at a discount for an extended period and may not ever realize their net asset value.

**Risks of convertible securities.** The market values of convertible securities tend to decline as interest rates increase and, conversely, to increase as interest rates decline. A downturn in equity markets may cause the price of convertible securities to decrease relative to other fixed income securities.

**Preferred stocks risk.** Preferred stocks may pay fixed or adjustable rates of return. Preferred stocks are subject to issuer-specific and market risks applicable generally to equity securities. In addition, a company's preferred stocks generally pay dividends only after the company makes required payments to holders of its bonds and other debt. Thus, the value of preferred stocks will usually react more strongly than bonds and other debt to actual or perceived changes in the company's financial condition or prospects. The market value of preferred stocks generally decreases when interest rates rise. Also, the market prices of preferred stocks are more sensitive to changes in the issuer's creditworthiness than are the prices of debt securities. Generally, under normal circumstances, preferred stocks do not

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carry voting rights. Preferred stocks may trade less frequently and in a more limited volume and may be subject to more abrupt or erratic price movements than other securities. Preferred stocks of smaller companies may be more vulnerable to adverse developments than preferred stocks of larger companies.

**Risks of warrants and rights.** If the price of the underlying stock does not rise above the exercise price before the warrant expires, the warrant generally expires without any value and the fund loses any amount it paid for the warrant. The failure to exercise subscription rights to purchase common shares would result in the dilution of the fund's interest in the issuing company.

**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. A general rise in interest rates could adversely affect the price and liquidity of fixed income securities and could also result in increased redemptions from the fund. 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.

Industries in the financials segment, such as banks, insurance companies, broker-dealers and real estate investment trusts (REITs), may be sensitive to changes in interest rates, credit rating downgrades, decreased liquidity in credit markets, and general economic activity and are generally subject to extensive government regulation.

**Derivatives risk.** Using stock index futures and options and other derivatives can increase fund losses and reduce opportunities for gains when market prices, interest rates, currencies 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. Derivatives are generally subject to the risks applicable to the assets, rates, indices or other indicators underlying the derivative. 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

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**Summary Prospectus**

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. Use of derivatives may have different tax consequences for the fund than an investment in the underlying security, and such differences may affect the amount, timing and character of income distributed to shareholders. The U.S. government and foreign governments have adopted and implemented or are in the process of adopting and implementing regulations governing derivatives markets, including mandatory clearing of certain derivatives, margin and reporting requirements. The ultimate impact of the regulations remains unclear. Additional regulation of derivatives may make them more costly, limit their availability or utility, otherwise adversely affect their performance or disrupt markets.

**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 and creates a risk of loss of value on 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. New derivatives regulations require the fund, to the extent it uses derivatives to a material extent, to, among other things, comply with certain overall limits on leverage. These regulations may limit the ability of the fund to pursue its investment strategies and may not be effective to mitigate the fund's risk of loss from derivatives.

**Valuation risk.** The sales price the fund could receive for any particular portfolio investment may differ from the fund's valuation of the investment, particularly for illiquid securities and securities that trade in thin or volatile markets or that are valued using a fair value methodology. These differences may increase significantly and affect fund investments more broadly during periods of market volatility. Investors who purchase or redeem fund shares on days when the fund is holding fair-valued securities may receive fewer or more shares or lower or higher redemption proceeds than they would have received if the securities had not been fair-valued or if a different valuation methodology had been used. The fund's ability to value its investments may also be impacted by technological issues and/or errors by pricing services or other third party service providers.

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**Liquidity risk.** Some securities and derivatives held by the fund may be or become impossible or difficult to purchase, sell or unwind, particularly during times of market turmoil. Illiquid securities and derivatives also may be difficult to value. If the fund is forced to sell an illiquid asset or unwind a derivatives position to meet redemption requests or other cash needs, the fund may be forced to sell at a loss.

**Redemption risk.** The fund may experience heavy redemptions that could cause the fund to liquidate its assets at inopportune times or at a loss or depressed value, or accelerate taxable gains or transaction costs, which could cause the value of your investment to decline.

**Cybersecurity risk.** Cybersecurity failures by and breaches of the fund's adviser, transfer agent, distributor, custodian, fund accounting agent or other service providers may disrupt fund operations, interfere with the fund's ability to calculate its NAV, prevent fund shareholders from purchasing, redeeming or exchanging shares or receiving distributions or receiving timely information regarding the fund or their investment in the fund, cause loss of or unauthorized access to private shareholder information, and result in financial losses to the fund and its shareholders, regulatory fines, penalties, reputational damage, or additional compliance costs.

**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 Russell Midcap Value Index, a broad-based measure of market performance that has characteristics relevant to the fund's investment strategies. <br>

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**Summary Prospectus**

You can obtain updated performance information by visiting https://www.amundi.com/usinvestors/Products/Mutual-Funds 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 fund began focusing on mid-cap securities during 1999.

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)

![](midcapval.jpg)

For the period covered by the bar chart:

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| | | | |
|:---|:---|:---|:---|
|  | **Returns** | **Period Beginning** | **Period Ending** |
| Highest Calendar Quarter | 16.77% | 10/01/2020 to | 12/31/2020 |
| Lowest Calendar Quarter | -29.25% | 01/01/2020 to | 03/31/2020 |

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**Average annual total return (%)**

(for periods ended December 31, 2022)

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| | | | | | |
|:---|:---|:---|:---|:---|:---|
|  | **1 Year** | **5 Years** | **10 Years** | **Since**<br> **Inception**<br>| **Inception**<br> **Date**<br>|
| Class A |  |  |  |  | 7/25/1990 |
| Return before taxes | -11.42 | 3.77 | &nbsp;&nbsp; 8.45 | &nbsp;&nbsp; 9.47 |  |
| Return after taxes on distributions | -13.72 | 1.99 | &nbsp;&nbsp; 6.34 | &nbsp;&nbsp; 7.70 |  |
| Return after taxes on distributions and <br> sale of shares<br>| &nbsp;&nbsp; -5.04 | 2.82 | &nbsp;&nbsp; 6.49 | &nbsp;&nbsp; 7.64 |  |
| Class C† | &nbsp;&nbsp; -7.58 | 4.12 | &nbsp;&nbsp; 8.17 | &nbsp;&nbsp; 7.02 | 1/31/1996 |
| Class K | &nbsp;&nbsp; -5.77 | 5.36 | &nbsp;&nbsp; N/A | &nbsp;&nbsp; 6.01 | &nbsp;&nbsp; 3/2/2015 |
| Class R | &nbsp;&nbsp; -6.43 | 4.57 | &nbsp;&nbsp; 8.65 | &nbsp;&nbsp; 8.46 | &nbsp;&nbsp; 4/1/2003 |
| Class Y | &nbsp;&nbsp; -5.85 | 5.26 | &nbsp;&nbsp; 9.39 | &nbsp;&nbsp; 7.61 | &nbsp;&nbsp; 7/2/1998 |
| Russell Midcap Value Index (reflects no <br> deduction for fees, expenses or taxes)<br>| -12.03 | 5.72 | 10.11 | 11.07 | 7/25/1990 |

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†

The performance of Class C shares does not reflect the 1% front-end sales charge in effect prior to February 1, 2004. If you paid a 1% sales charge, your returns would be lower than those shown above.

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 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. Returns after taxes on distributions and sale of fund shares are higher than returns before taxes for certain periods shown because they reflect the tax benefit of capital losses realized on the sale of fund shares.

After-tax returns are shown only for Class A shares. After-tax returns for Class C, Class K, Class R and Class Y shares will vary.

**Management** 

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| | |
|:---|:---|
| **Investment adviser** | Amundi Asset Management US, Inc. ("Amundi <br> US")<br>|
| **Portfolio management** | Timothy P. Stanish, Vice President and EVA <br> (economic value added) Analyst of Amundi US <br> (lead portfolio manager) (portfolio manager of the <br> fund since 2018); and John Arege, Vice President of <br> Amundi US (portfolio manager of the fund since <br> February 2022)<br>|

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**Summary Prospectus**

**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 in writing or by telephone: Pioneer Funds, P.O. Box 534427, Pittsburgh, PA 15253-4427, 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. Generally, the initial investment for Class K or 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 K or Class Y shares, as applicable. There is no minimum additional investment amount for Class K or Class Y shares. There is no minimum investment amount for Class R shares.

**Tax information**

The fund intends to make distributions that may be taxed as ordinary income, qualified dividend 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 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.

23458-13-0323

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