European regulators slammed a handful of major banks with a billion dollar fine for rigging forex markets.

EU antitrust regulators have fined Barclays, Citigroup, J.P. Morgan, and Royal Bank of Scotland a massive €1.07 billion ($ 1.2 billion) for manipulating the spot forex market for 11 currencies.

The Commission’s probe, which began in September 2013, revealed that some specific foreign exchange traders, employing online chat rooms, conspired in trading plans and occasionally adjusted their trading methods to squeeze out additional profits. The European Commission affirmed the market-rigging occurred from 2007 through 2013 where forex traders of the five banks “exchanged sensitive information and trading plans, and occasionally coordinated their trading strategies through various online professional chatrooms.”

The EU competitors enforcer asserted the bulk of the traders knew each other on an individual basis and set up chat rooms such as “Essex Express ‘n the Jimmy”, which was given this name because all of them other than “James” lived in Essex, to the east of London, and met on their train commute to the British capital. Other names for spaces were the “Three Way Banana Split” and “Semi-Grumpy Old Men”.

In a release, EU Commissioner Margrethe Vestager explained, “Today we have fined Barclays, The Royal Bank of Scotland, Citigroup, J.P. Morgan and MUFG Bank and these cartel decisions send a clear message that the Commission will not tolerate collusive behavior in any sector of the financial markets. The behavior of these banks undermined the integrity of the sector at the expense of the European economy and consumers.”

Vestager also noted “Companies and people depend on banks to exchange money to carry out transactions in foreign countries. Foreign exchange spot trading activities are one of the largest markets in the world, worth billions of euros every day.”

Banks fined for rigging the forex system

Citigroup felt the brunt of the fine, with a €310.8 m penalty, followed by fines of €249.2 million and €228.8 million for RBS and JPMorgan, respectively, the European Commission said on Thursday. Barclays was also fined €210.3 million and Mitsubishi UFJ Financial Group (MUFG) must pay nearly €70 million as part of the settlement with the EU’s antitrust regulator.

While relatively large, these antitrust fines are lower than a €1.3 bn penalty for banks for rigging Euribor rates and below a record €3.8 bn penalty for collusion between truck makers.

The news breaks as the sleeping forex market struggles to break out.