JPMorgan reveals a DOJ criminal investigation involving its foreign exchange business

JPMorgan Chase says the Justice Department has opened a criminal investigation into its foreign exchange business.

The announcement by the nation's largest bank follows a similar disclosure Thursday by Citigroup. Banks in the U.S. and abroad are facing allegations that they manipulated foreign-exchange rates. Besides the Justice Department, JPMorgan says civil enforcement authorities and foreign regulators are also investigating its foreign exchange business.

The New York bank said late Monday in a filing with the U.S. Securities and Exchange Commission that it had boosted the amount of money set aside for legal expenses. It now has $5.9 billion in reserve, up from the $4.6 billion it reported in August.

JPMorgan Chase & Co. has paid billions in penalties since the financial crises related to mortgages and huge investor losses.