New Trading Case Casts a Deeper Shadow on a Hedge Fund Mogul .

By Dealbook

In 2010, the billionaire hedge fund manager Steven A. Cohen gave a rare interview to Vanity Fair. He said that he wanted to combat persistent rumors that his firm, SAC Capital Advisors, routinely violated securities laws by trading on confidential information.

“In some respects I feel like Don Quixote fighting windmills,” Mr. Cohen said at the time. “There’s a perception, and I’m trying to fight that perception.”

Federal prosecutors only heightened that perception on Tuesday, bringing a criminal case against a former SAC employee in whatPreet Bharara, the United States attorney in Manhattan, who brought the charges in Federal Distr