John Arnold – Billionaire

John Arnold shocked the hedge fund world in 2012 when, at just 38 years old, he announced he was retiring. One of the most successful energy traders alive, Arnold worked at Enron early in his career, earning the disgraced company a reported $750 million the year the firm declared bankruptcy. From its ashes, Arnold built his own hedge fund, taking former Enron colleagues to his newly founded Centaurus Advisors. He churned out triple-digit returns for several years and minted a billion-dollar fortune in the process. Now he spends most of his time giving away his fortune, employing the same contrarian philosophy that made him billions as an energy trader. A Democrat who favors pension reform and works with the Koch brothers on criminal justice reform, Arnold has backed efforts to study dietary guidelines, reduce drug costs and measure pretrial risk. He runs his philanthropic foundation with his wife, Laura.

Source:forbes