Summary Prospectus by Investment Company (Form 497K)

						PRIMECAP Odyssey Stock Fund Summary Prospectus February 28, 2026
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, Reports to Shareholders, Statement of Additional Information and other information about the Fund online at http://www.primecap.com. You may also obtain this information at no cost by calling 1-800-729-2307 or by email at [email protected]. The Fund's Prospectus and Statement of Additional Information dated February 28, 2026 are incorporated by reference into this Summary Prospectus

Investment Objective

The PRIMECAP Odyssey Stock Fund seeks to provide long-term capital appreciation.

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.

Shareholder Fees (Fees paid directly from your investment)
Maximum sales charge on purchases or reinvested dividends			None
Redemption or exchange fees			None

Annual Fund Operating Expenses (Expenses that you pay each year as a percentage of the value of your investment)
Management fees			0.55%
Other expenses			0.12%
Total annual fund operating expenses			0.67%

Example

The example below 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. 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:

1 Year						3 Years						5 Years						10 Years
$68						$214						$373						$835

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 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 9% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests primarily in the common stocks of U.S. companies. The Fund invests at least 80% of its assets in stocks (the Fund will provide its shareholders with at least 60 days' prior notice of any change in this non-fundamental investment policy). The Fund may invest in stocks across all market sectors and market capitalizations, though it has historically invested primarily in large- and mid-capitalization companies. Because of the bottom-up selection process of PRIMECAP Management Company (the "Advisor"), the Fund may maintain a significantly overweight or underweight position in a particular sector relative to the S&P 500® Index, a market capitalization-weighted index of 500 large-capitalization stocks commonly used to represent the U.S. equity market, at any time. The Fund may also invest substantial assets in foreign securities through depository receipts or stocks traded on U.S. or foreign exchanges.

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The Advisor, through its fundamental research, seeks to identify stocks with attractive growth prospects that are trading at reasonable valuations. The Advisor looks for companies that, in its judgment, will grow faster and/or will be more profitable than their current market valuations suggest and for companies with asset values that are not adequately reflected in their stock prices. The Advisor may sell a stock if its market price appears to have risen above its fundamental value, if other securities appear to be more favorably priced, if the reasons for which the stock was purchased no longer hold true, or for other reasons. The Advisor maintains a long-term focus and attempts to identify stocks that it believes will outperform the S&P 500® Index over a three- to five-year time frame.

Principal Risks

You may lose money by investing in the Fund. You should expect the Fund's share price and total return to fluctuate within a wide range, like the fluctuations of the overall stock market. The Fund's performance could be hurt by:

•Stock market risk. The chance that stock prices overall will decline. Stock markets tend to move in cycles, with periods of rising prices and periods of falling prices.

•Manager risk. The chance that, as a result of poor security selection by the Advisor, the Fund may underperform relative to its benchmarks or other funds with similar investment objectives.

•Investment style risk. The chance that returns from the mix of small-, mid-, and large-cap stocks in the Fund's portfolio will trail returns from the overall stock market. Historically, small- and mid-cap stocks have been more volatile in price than the large-cap stocks that dominate the overall stock market, and they often perform quite differently. Additionally, from time to time, growth stocks may be more volatile than the overall stock market.

•Sector-focus risk. Investing a significant portion of the Fund's assets in one sector of the market exposes the Fund to greater market risk and potential monetary losses than if those assets were spread among various sectors. If the Fund's portfolio is overweighted in a certain sector, any negative development affecting that sector will have a greater impact on the Fund than a fund that is not overweighted in that sector.

•Asset concentration risk. The chance that, because the Fund tends to invest a high percentage of its assets in its largest holdings, the Fund's performance may be hurt disproportionately by the poor performance of relatively few stocks.

•Issuer risk. Issuer-specific attributes may cause a security held by the Fund to be more volatile than the market generally. An individual security may also be affected by factors related to the industry or sector of the issuer or the securities markets as a whole, and conversely an industry or sector or the securities markets may be affected by a change in financial condition or another event affecting a single issuer.

•Foreign securities risk. The chance that the value of foreign securities will be adversely affected by the political and economic environments and other overall economic conditions in the countries where the Fund invests. Investing in foreign securities involves: country risk, which is the chance that domestic events - such as political upheaval, financial troubles, corruption, or natural disasters - will weaken a country's securities markets; and currency risk, which is the chance that the value of a foreign investment, measured in U.S. dollars, will decrease because of unfavorable changes in currency exchange rates. Foreign companies are generally subject to different legal and accounting standards than U.S. companies, and foreign financial intermediaries may be subject to less supervision and regulation than U.S. financial firms.

•Small- and mid-cap stocks risk. The chance that small- and mid-cap stocks may trade less frequently or in more limited volume than those of larger, more established companies; may fluctuate in value more; and, as a group, may suffer more severe price declines during periods of generally declining stock prices.

•U.S. Administration Foreign Policy and Government Restructuring Risk. Since the change in the U.S. presidential administration in 2025, the administration has pursued an aggressive foreign policy agenda, including through suggestions that the United States should control certain sovereign foreign territories, attempts to restructure federal government agencies with international influence, and the imposition of tariffs and trade barriers on certain foreign countries, including China and long-time U.S. allies. These and other similar actions may have unforeseen consequences on the economy and markets generally, and could negatively impact the Fund.

Fund Performance

The following performance information indicates some of the risks of investing in the Fund by showing changes in the Fund's performance over time. The bar chart below illustrates the Fund's total return for each of the last ten calendar years. The table below illustrates the Fund's average annual return over time compared with a domestic broad-based securities market index. The Fund's past

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performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future. Unlike the Fund's returns, the index returns do not reflect any deductions for fees, expenses, or taxes. For additional information on the index, please see "Index Description" on page 42 of the statutory prospectus. Updated performance is available on the Fund's website at www.primecap.com.

Calendar Year Total Return

During the period shown in the bar chart, the Fund's highest quarterly return was +17.39% for the quarter ended December 31, 2020, and the lowest quarterly return was -25.66% for the quarter ended March 31, 2020.

Average Annual Total Returns as of December 31, 2025

			1 Year			5 Year			10 Year			Annualized Since Inception (November 1, 2004)
PRIMECAP Odyssey Stock Fund
Return Before Taxes			25.59%			13.88%			13.45%			11.25%
Return After Taxes on Distributions			19.18%			10.33%			11.12%			10.03%
Return After Taxes on Distributions and Sale of Fund Shares			19.77%			10.58%			10.77%			9.62%
S&P 500® Index (reflects no deduction for fees, expenses, or taxes)			17.88%			14.42%			14.82%			11.00%

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, and after-tax returns shown may not be relevant to investors who hold their Fund shares through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts ("IRAs").

The "Return After Taxes on Distributions and Sale of Fund Shares" is higher than other return figures when a capital loss occurs upon the redemption of Fund shares.

Investment Advisor

PRIMECAP Management Company is the investment advisor for the PRIMECAP Odyssey Stock Fund.

Portfolio Managers

Theo A. Kolokotrones, Chairman Emeritus, Joel P. Fried, Chairman, Alfred W. Mordecai, President, M. Mohsin Ansari, Vice Chairman, and James Marchetti, Executive Vice President, each independently manages a portion of the PRIMECAP Odyssey Stock Fund. Each of Messrs. Kolokotrones, Fried, and Mordecai has managed his respective portion of the Fund since its inception in 2004. Mr. Ansari has managed his portion of the Fund since April 2012. Mr. Marchetti has managed his portion of the Fund since January 2014.

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Purchase and Sale of Fund Shares

Investors may purchase, exchange, or redeem Fund shares on any business day by written request or telephone. Shares may be purchased or redeemed by wire transfer. Certain transactions may be conducted online on the Fund's website. You can conduct transactions by mail at PRIMECAP Odyssey Funds, c/o U.S. Bank Global Fund Services, P.O. Box 219258, Kansas City, Missouri 64121-9258 (for regular mail) or c/o U.S. Bank Global Fund Services, 801 Pennsylvania Ave, Suite 219258, Kansas City, Missouri 64105-1307 (for overnight mail); by telephone at 1-800-729-2307; or online at www.primecap.com. Redemptions by telephone are only permitted if the Fund has previously received appropriate authorization. Investors who wish to purchase, exchange, or redeem Fund shares through a broker-dealer should contact the broker-dealer directly. The minimum initial investment in the Fund is $2,000 for regular accounts and $1,000 for retirement accounts; subsequent investments must be at least $100.

Tax Information

The Fund's distributions will normally be taxed as ordinary income, qualified dividend income, capital gains, or a combination of the three, unless you are investing through a tax-advantaged arrangement, such as a 401(k) plan or an IRA.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase the Fund through a broker-dealer or other financial intermediary, 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 to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary's website for more information.

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