34. Barclays 2015 ($2,378 million)

UK and US authorities fined Barclays US$2.4 billion in 2015 after the London-based bank pleaded guilty to foreign exchange rate manipulation. Barclays’ forex rigging penalty was the largest of six banks, including RBS, JPMorgan and Citigroup, that were fined a combined total of US$5.7 billion on 20 May 2015.