Three Britons who are former traders for major banks have pleaded not guilty to rigging prices for dollars and euros in the foreign exchange market.
Richard Usher, Rohan Ramchandani and Chris Ashton appeared before a federal judge in New York to face criminal charges of market manipulation.
The trio were traders for affiliates of JP Morgan Chase, Barclays, RBS and Citicorp.
Prosecutors claim the men, and other unnamed co-conspirators, used an internet chatroom called "The Cartel" to conspire in fixing prices.
The US Justice Department also alleges they helped control prices "by refraining from entering bids/offers or trading at certain times".
The banks affiliated with the former traders settled with the Justice Department in 2014, together agreeing to pay more than $2.5bn (£1.9bn) in fines.
Ashton, Ramchandani and Usher were charged in January, and agreed last month to appear in Manhattan rather than fight extradition.
The charges they face carry a maximum penalty of 10 years in prison and a $1m (£770,000) fine.
However, the Justice Department says this fine can be increased to twice the damage suffered by victims or twice the gain derived from the crime.
Ashton was Barclays' global head of spot currency trading, Ramchandani was Citigroup's head of G-10 spot currency trading, and Usher was the chief currency spot trader for JP Morgan.
American officials have taken aggressive action in recent years to prosecute interest rate and foreign exchange manipulation by major banks.
Earlier on Monday, the French giant BNP Paribas was fined $246m (£188m) by the Federal Reserve - also over foreign exchange practices.
(c) Sky News 2017: <a href="http://news.sky.com/story/british-trio-plead-not-guilty-to-fixing-prices-for-dollars-and-euros-10952249">British trio plead not guilty to fixing prices for dollars and euros</a>, source Sky News