3. Brian Hunter (Loss: $ 6.6 billion)
Brian Hunter was a trader of natural gas from the Amaranth Advisors hedge fund firm. The founder of Amaranth Advisors, Nicholas Amounis allowed Hunter control of the firm’s trades. Hunter traded under the assumption that the gas price in the winter of 2006-2007 will soar relative to the previous summer’s prices. Unfortunately the market behaved differently and took a sharp turn against his predictions. Amaranth Advisors had to be dissolved entirely after losing about $6.6 billion.