Strategy. 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 … Show more… 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. 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. Show less