Steve Ballmer

Former Microsoft CEO Steve Ballmer rounds out the top 10 with an estimated net worth of ~$110 billion, a fortune built almost entirely on the Microsoft stock he accumulated during his 14-year tenure as CEO from 2000 to 2014. Ballmer purchased the NBA's Los Angeles Clippers for $2 billion in 2014 — a deal widely mocked at the time but now considered one of the best sports investments ever as the franchise's value has climbed past $5 billion. He remains one of Microsoft's largest individual shareholders.