“This has shaken our company to the core,” CEO Jamie Dimon said.

The bank said managers tied to the bad trade had been dismissed without severance pay and that it planned to revoke two years’ worth of pay from each of those executives.

JPMorgan said it had lost $US4.4 billion because of the trade from April through June, and its chief financial officer said the bank had lost an additional $US1.4 billion in the first three months of the year.

Mr Dimon’s original estimate of the loss from the bad trade, disclosed in a surprise conference call with Wall Street analysts on May 10, was $US2 billion.

The bank said an internal investigation, including emails and voice messages, had called into question the values that traders placed on certain bets, and that the traders may have been seeking to mask losses.

The Securities and Exchange Commission and Justice Department did not immediately respond to requests for comment.

Mr Dimon told Congress last month that the trade was meant to hedge risk to the company and protect it in case “things got really bad” in the global economy. Instead, the trade has backfired and damaged the bank’s reputation.