The $400 million of cumulative losses that Citigroup Inc, Deutsche Bank AG and Barclays Plc are said to have suffered from the Swiss central bank's decision to end the cap on the franc may be followed by others in coming days.

"The losses will be in the billions - they are still being tallied," said Mark T. Williams, an executive-in - residence at Boston University specializing in risk management. "They will range from large banks, brokers, hedge funds, mutual funds to currency speculators. There will be ripple effects throughout the financial system."

Citigroup, the world's biggest currencies dealer, lost more than $150 million at its trading desks, a source said last week.