JPMorgan Chase said Friday that a bad trade had cost the bank $5.8 billion this year, almost triple its original estimate, and raised the prospect that traders had improperly tried to conceal the blunder.

"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.