During his 15-year tenure as CEO and chairman of UnitedHealth Group Inc., McGuire turned the regional health insurer into the second largest managed care company in the U.S. He received his thank yous in the form of stock options$1.6 billion of them, to be exactbut he took some of them on the days the company's stock price hit yearly lows, profiting when the stocks went up again. McGuire was asked to leave in October 2006 after federal prosecutors and the IRS requested documents concerning his stock options and executive compensation. He later agreed to return $600 million in various payback agreements, including one with the SEC. But McGuire retained about $800 million in options.