FBI chief confirms JPMorgan Chase probe (CBS/AP) WASHINGTON - FBI Director Robert Mueller said Wednesday the bureau has launched a preliminary investigation of JPMorgan Chase & Co. (JPM) following a $2 billion trading loss at the bank. Mueller's comment at a Senate Judiciary Committee hearing was the first on-the-record confirmation of the probe. On Tuesday, a law enforcement official said that the FBI's New York office is heading an inquiry into the JPMorgan loss. "All I can say is we've opened up a preliminary investigation," Mueller told the Senate panel. Mueller said that opening a preliminary investigation "depends on a number of factors," which he did not enumerate. Shareholders sue JPMorgan over $2B trading loss VIDEO: JPMorgan CEO keeps titles, despite angry shareholders Under attorney general guidelines for FBI operations, a preliminary investigation may be initiated on the basis of any allegation or information indicative of possible criminal activity. Time limits are set for completion of preliminary investigations usually six months, although six-month extensions can be granted. Extensions of preliminary investigations beyond a year must be approved by FBI headquarters.