JPMorgan Chase says top managers tied to its highly publicized trading blunder have been dismissed without severance pay. The bank says it's taking back two years' pay from those officials.

The bank is discussing the trading loss with Wall Street analysts. It says the loss from the trade in the most recent quarter was $4.4 billion. The bank's original estimate was $2 billion.

JPMorgan also says it has discovered information that "raises questions about the integrity" of values placed on certain trades.

CEO Jamie Dimon says: "We're not making light of this error, but we do think it's an isolated event."