Federal prosecutors have unveiled charges against the hedge fund giant SAC Capital Advisors for alleged securities and wire fraud. The indictment accuses SAC of enabling a massive insider trading scheme that reaped hundreds of millions of dollars in profit for the firm and its billionaire owner, Steven Cohen, over more than a decade. Preet Bharara, the U.S. attorney for the Southern District of New York, said SAC’s scheme was unprecedented in size for a U.S. hedge fund.

U.S. Attorney Preet Bharara: “When so many people from a single hedge fund have engaged in insider trading, it is not a coincidence. It is instead the predictable product of substantial and pervasive institutional failure. As alleged, SAC trafficked in inside information on a scale without any known precedent in the history of hedge funds. As described in the indictment, the scope of illegal trading was deep, and it was wide. It spanned more than a decade in time, involved the securities of at least 20 public companies, extended across multiple sectors of the economy, and benefited SAC to the tune of at least hundreds of million dollars.”

The charges against SAC mark a rare departure for federal prosecutors in that they chose to avoid a “deferred prosecution agreement” that allows a firm to avoid indictment if they agree to change their behavior.