Ajit Jain

Jain joined Berkshire Hathaway in 1986 with no insurance background and built its reinsurance business into a source of tens of billions of dollars of float, the money Berkshire invests. He priced unusual risks, from huge catastrophe covers to sporting events, with discipline about walking away when prices were too low. Buffett repeatedly said Jain had made more money for shareholders than he had, yet he gave almost no interviews.