FBI's Mueller confirms JPMorgan preliminary probe WASHINGTON (Reuters) - FBI Director Robert Mueller on Wednesday confirmed that the agency has opened a "preliminary investigation" into JPMorgan Chase & Co (JPM.N), the nation's largest bank. JPMorgan disclosed last week that it had suffered a multibillion-dollar trading loss due to a failed hedging strategy. A person familiar with the matter said on Tuesday that the FBI's New York office has opened a preliminary probe into the loss, which has been estimated at more than $2 billion. Mueller was testifying before the Senate Judiciary Committee. When pressed by lawmakers about what legal violations JPMorgan may have committed, Mueller said: "All I can say is we've opened a preliminary investigation." Mueller also said the timing of the investigation "depends on a number of factors." He did not elaborate. Reporting By Lily Kuo; Editing by Gerald E. McCormick