NEW YORK (CNNMoney) – The director of the Federal Bureau of Investigation said Wednesday that the agency has opened an investigation into JPMorgan Chase, the nation’s largest bank.
“All I can say is that we have opened a preliminary investigation,” Robert Mueller said in response to questions at an FBI oversight hearing on Capitol Hill.
Last week JPMorgan disclosed it had suffered a $2 billion trading loss on a series of complex bets on credit default swaps, a kind of derivative sometimes used to hedge against risk.
It remains unclear what potential crimes the FBI may be investigating, and Mueller declined to answer questions on that topic Wednesday, saying only that the agency had opened a preliminary investigation.
Media reports also indicate the Securities and Exchange Commission has launched an investigation of its own, a move that would be expected following a trading loss of the magnitude suffered by JPMorgan.
JPMorgan shares were up slightly in trading on Wednesday, but are still down more than 11% over the previous five trading sessions.