Three-time Masters winner Phil Mickelson, shown at the Honda Classic golf tournament last year, benefited from insider trading of Dean Foods stock, according to U.S. officials. He has not been charged. Luis M. Alvarez/AP hide caption
U.S. Attorney Preet Bharara mounted a high-profile investigation of insider trading, but an appeals court has made convictions harder to get Kathy Willens/AP hide caption
Authorities say several publicly traded companies, including Clorox, Caterpillar and Viacom, had press releases stolen and used to implement an insider-trading scheme. Spencer Platt/Getty Images hide caption
Billionaire financier Carl Icahn is reportedly at the center of an insider trading probe being conducted by the FBI and SEC. Charles Rex Arbogast/AP hide caption
BP Mobile Incident Commander Keith Seilhan talks with oil cleanup workers in Gulf Shores, Ala., in July 2010. Seilhan has settled with SEC regulators who say he avoided $100,000 in stock and options losses by trading on inside information related to the spill. Dave Martin/AP hide caption
Former SAC Capital Advisors portfolio manager Mathew Martoma walks out of the courthouse in downtown Manhattan, New York, on Thursday. Eduardo Munoz/Reuters/Landov hide caption
Preet Bharara, United States Attorney for the Southern District of New York speaks at a news conference July 25, 2013 about a federal indictment against SAC Capital. Timothy Clary/AFP/Getty Images hide caption
Rajat Gupta on Wednesday as he arrived at the federal courthouse in Manhattan. Emmanuel Dunand /AFP/Getty Images hide caption
Rep. Spencer Bachus, R-Ala. Chip Somodevilla/Getty Images hide caption