This large and mid-capitalization growth fund is managed with a long-term outlook, exceptionally low portfolio turnover, and a well-established investment framework. Since its inception in 1984, the advisor, PRIMECAP Management Company, has employed a distinct strategy where multiple portfolio managers independently oversee portions of the fund, thereby promoting a broad range of investment ideas. A key risk is its potential for significant concentration in specific sectors, notably technology and health care. Such focus can lead to heightened short-term performance volatility when these industries experience significant shifts. This fund is generally best considered a complementary addition to an already diversified portfolio for investors with an extended time horizon.