The Oakmark Fund is a mutual fund that primarily invests in U.S. stocks, focusing on companies that are undervalued compared to their intrinsic worth. Managed by Harris Associates, the fund aims to achieve long-term capital appreciation by selecting high-quality businesses with strong fundamentals. Founded in 1991, the Oakmark Fund employs a value investing strategy, which means it looks for stocks that are trading for less than their true value. The fund is known for its disciplined approach and has a history of delivering competitive returns to its investors over time.