Warren Buffett has served as the CEO of the Berkshire Hathaway (NYSE: BRK.A)(NYSE: BRK.B) holding company since 1965. Had you invested $1,000 in Berkshire stock when he took the helm, it would have been worth a whopping $44.7 million at the end of 2024. Buffett and his team oversee a $265 billion portfolio of stocks and securities, in addition to several wholly owned subsidiaries.