Dimon called the actions an “egregious failure” and said the bank could lose up to $1 billion more, according to Bloomberg.

The failures came from the company’s chief investment office, based in London, that hedges risk for JPMorgan. According to Bloomberg, over the past few years, the CIO has been taking riskier positions.

JPMorgan’s stock decline this morning marks the biggest drop for the company in nine months. Though JPMorgan, known as one of the banks that stayed afloat during the financial crisis, lost $2 billion last quarter, net losses are actually around $800 million because of increases in sales from its available-for-sale credit portfolio, according to Bloomberg.

The loss has brought on questions of how the major banks are handling risk management and revived the debate over the Volcker rule, a regulation Dimon has been outspoken against. The Volcker rule is a regulation that was passed as part of the Dodd-Frank Wall Street Reform and Consumer Protection Act that bans proprietary trading. Dimon told Bloomberg that JPMorgan’s CIO was not involved in proprietary trading.

Despite the JPMorgan’s losses, the stock market bounced back on Friday after a positive consumer confidence report and a report showing that inflation didn’t increase significantly in April.