Secret Currency Traders’ Club Devised Biggest Market’s Rates

It’s 20 minutes before 4 p.m. in London and currency traders’ screens are blinking red and green. Some dealers have as many as 50 chat rooms crowded onto four monitors arrayed in front of them like shields. Messages from salespeople and clients appear, get pushed up by new ones and vanish from view. Orders are barked through squawk boxes.

This is the closing “fix,” the thin slice of the day when foreign-exchange traders buy and sell billions of dollars of currency in the largely unregulated $5.3-trillion-a-day foreign-exchange market, the biggest in the world by volume, according to the Bank for International Settlements. Their trades help set the benchmark WM/Reuters rates used to value more than $3.6 trillion of index funds held by pension holders, savers and money managers around the world.