In the fall of 2008, Aubrey McClendon of Chesapeake Energy sold "substantially all" of his 33.4 million shares at a $2 billion paper loss after he faced margin calls related to loans he used to buy more of the Oklahoma City-based company's stock. That year, Chesapeake Energy disclosed that it gave McClendon a $75 million cash bonus. As of its 2011 proxy statement, Chesapeake Energy said it's banned the use of margin accounts by corporate executives.