Royal Bank of Scotland and Barclays are facing penalties of about $1billion each from US authorities for their alleged role in the manipulation of currency markets. The US Justice Department is looking to fine four banks – RBS, Barclays, Citigroup and JP Morgan Chase – to settle accusations of criminal activity in the currency markets. In total the US authorities are seeking penalties of about $4 billion. Meanwhile, UBS has been granted immunity from prosecution, as it was the first bank to notify US authorities of possible misconduct in the foreign exchange market. The banks have already agreed to pay regulators about $4.3bn for their involvement in the rigging of currency rates.