S tewart Horejsi is an American investor who amassed a multi-billion dollar fortune through a single, life-changing investment decision. He is the son of the founder of a family-owned welding supply company in Kansas. In 1980, after reading a biography of Warren Buffett, Horejsi became a devoted follower of his value investing philosophy. Convinced of Buffett's genius, he took a significant portion of his family's company's profits and began buying shares of Buffett's holding company, Berkshire Hathaway.

At the time, Berkshire Hathaway's shares were trading for a few hundred dollars each. Horejsi's initial investment was a huge success, and he continued to buy more shares over the years. As Buffett built Berkshire into one of the largest and most successful companies in the world, the value of Horejsi's early and concentrated bet soared, turning his family into multi-billionaires. He is now one of the largest non-Buffett individual shareholders in the company. He has since diversified his family's wealth into other areas, including real estate and private equity, and has become a major philanthropist.