US and British regulators have fined six major global banks nearly $6bn for rigging the world's currency market.
Wednesday's decision is the first time in decades that major players in the financial industry have admitted to criminal wrongdoing and were punished on such a large scale.
The landmark settlement included guilty pleas from Barclays Bank, JPMorgan Chase, Citicorp and the Royal Bank of Scotland for conspiring to manipulate the massive currency market, as well as a guilty plea from Switzerland's UBS, for rigging benchmark interest rates.
These five banks agreed to a record $2.5bn in criminal penalties, the largest set of antitrust fines ever obtained by the US Department of Justice.
All five, plus the Bank of America, will also pay more than $1.8bn in fines to the US Federal Reserve over "unsafe and unsound practices" in forex markets.
The massive settlement addresses what regulators described as a brazen scheme by financial heavyweights to orchestrate trades in the $5.3tn-per-day global foreign exchange market in ways that cheated
clients and bolstered their own profits.
'Brazenly illegal behaviour'
Traders from the banks, communicating in a chat room referred to as The Cartel, agreed to withhold bids or offers for euros or dollars at distinct times to protect each other's trading positions, the Justice Department said.
The bank's chat room nickname "aptly describes the brazenly illegal behaviour they were engaged in on a near-daily basis", Loretta Lynch, the US attorney general, said.
"They acted as partners - rather than competitors - in an effort to push the exchange rate in directions favourable to their banks but detrimental to many others.
"And their actions inflated the banks' profits while harming countless consumers, investors and institutions around the globe."
Wednesday's settlement follows earlier agreements between large banks and global regulators in a massive global probe into rigging foreign exchange trading that has ensnared most large banks and resulted in numerous firings and suspensions of individual traders.
Banks have now agreed to nearly $9bn in fines for manipulating forex rates.
The size of penalties on individual banks ranged from the hundreds of millions of dollars to $2.4bn for British bank Barclays, depending on a bank's involvement in the scheme and whether it had joined an earlier settlement with some regulators late last year.
The Barclays sum was high because it had not participated in the earlier deal.
"Put simply, Barclays employees helped rig the foreign exchange market," said Benjamin Lawsky, the head of the Department of Financial Services for New York State.
"They engaged in a brazen 'heads I win, tails you lose' scheme to rip off their clients."
In Wednesday's deals, in addition to forex-manipulation charges, both Barclays and UBS were fined for violating a 2012 settlement for conspiring to rig Libor, the global commercial interest rate benchmark used to peg millions of rate-sensitive contracts and loans around the world.
UBS said that it will plead guilty to fraud in the US over the Libor interest rate-rigging scandal and pay $203 million in fresh fines.
The justice department granted the Swiss bank conditional immunity in its foreign exchange probe for cooperating with the investigation.
However, the justice department demanded the guilty plea on Libor after concluding UBS's role in foreign exchange breached its 2012 non-prosecution agreement on Libor.