#9 Warren Buffett

Warren Buffett built his fortune through Berkshire Hathaway, the Omaha-based conglomerate he took control of in 1965 and spent six decades transforming from a failing textile mill into a sprawling holding company spanning insurance (GEICO, General Re), railroads (BNSF), energy (Berkshire Hathaway Energy), and a public-equities portfolio (Apple, Coca-Cola, American Express, and dozens more) alongside wholly owned businesses like See's Candies and Dairy Queen. Unlike most people on this list, almost none of his wealth came from founding a single breakout company — it compounded over roughly 70 years of disciplined value investing, applying lessons from his teacher Benjamin Graham at Columbia Business School.

Buffett stepped down as Berkshire's CEO at the end of 2025 after the board approved his hand-picked successor, Greg Abel, who took over as President and CEO effective January 1, 2026. Buffett, then 95, remained on as chairman and attended the May 2026 annual shareholder meeting in Omaha as an audience member for the first time in six decades rather than leading it from the stage. He has also been giving away his fortune faster than it can compound: in July 2026 he redirected nearly $6 billion in Berkshire shares to four family foundations, notably excluding the Gates Foundation from his annual gift for the first time in 20 years, and restated a goal of disposing of his entire Berkshire stake by around 2034.