Global regulators fined five big banks $3.38 billion on Wednesday after uncovering a foreign exchange scandal.

According to British, American and Swiss regulators, the world's largest banks manipulated the foreign currency markets, where over $5 trillion is traded each day, in order to earn extra profits. As a result, Citibank, HSBC, JPMorgan Chase, RBS and UBS settled on a collective payment of $1.4 billion to the U.S. Commodity Futures Trading Commission and about $1.75 billion to the U.K.'s Financial Conduct Authority, reports The New York Times.

The Foreign exchange rates, which are set on a daily basis, affect the price of imported goods, company earnings and different investments held by pension funds.

However, between June 2008 and Oct. 2013, "ineffective controls at the banks" allowed traders to share confidential information and collude with traders at other institutions in an effort to fix rates and increase profits for their own banks, at the expense of clients, said the Financial Conduct Authority, according to the Los Angeles Times.

"Traders at different banks formed tight knit groups in which information was shared about client activity, including using code names to identify clients without naming them," the FCA explained.

According to Aitan Goelman, the director of enforcement at the U.S. Commodity Futures Trading Commission, setting a benchmark rate is not just "another opportunity for banks to earn a profit."

"Countless individuals and companies around the world rely on these rates to settle financial contracts, and this reliance is premised on faith in the fundamental integrity of these benchmarks," he continued  according to CNN Money. "The market only works if people have confidence that the process of setting these benchmarks is fair, not corrupted by manipulation by some of the biggest banks in the world."

Traders were given leverage to behave unacceptably because the banks failed to manage obvious risks, said the FCA.

In addition to the hefty fine, banks and individual employees may also face criminal charges.