The FBI has opened an inquiry into the multibillion-dollar trading losses at JPMorgan Chase, stepping up pressure on the bank after key U.S. agencies said they were looking into high-risk trades that first drew regulators’ attention last month.The news did little to spook investors, who sent the stock higher Tuesday, or shareholders, who backed embattled Chief Executive Jamie Dimon at the bank’s annual shareholders meeting, with a vote rejecting a proposal to split the jobs of CEO and chairman.Though investors mostly gave Dimon a pass, pressure mounted on the bank to reclaim some of the millions of dollars it paid to the executives who oversaw the trades. Dimon said JPMorgan would pursue more disciplinary action against those responsible."We will do the right thing. That may well include clawbacks,” he told reporters after the annual meeting.The timing on any such move was not clear, though, and the various regulatory probes could add complications. A source familiar with the situation said Tuesday that U.S. and UK regulators first raised concerns with senior management in April.A separate source familiar with the FBI probe, opened by the agency’s New York office, described it as preliminary. The probe was seen in some quarters as a necessary public step, given the ongoing debate in Washington about bank regulation, and one expert said it raised the level of concern around what happened.