JP Morgan yesterday dipped into the funds it has set aside to cover a tangle of legal and regulatory difficulties to settle charges that it "recklessly disregarded the fundamental precept on which market participants rely".
The admission came over the activities of its so called "London Whale" trader whose huge positions led to multi-billion dollar losses.
The bank will also pay a $100m (£63m) fine to the US Commodity Futures Trading Commission (CFTC). It has already shelled out $920m over the affair to regulators on both sides of the Atlantic.
JP was forced to admit its traders behaved "recklessly", although it will be hoping the formulation agreed with the CFTC will protect it from civil actions.
In charging the bank with "employing a manipulative device", the regulator made use of new powers granted it under the 2010 Dodd Frank overhaul of financial regulation in the US. However, Republican commissioner Scott O'Malia opposed the deal saying the CFTC should have "taken more time to investigate whether the company is liable for a more serious violation, namely price manipulation".
The bank last week said legal costs totalling $9.2bn threw it into a third-quarter loss.
The bank and its chief executive, Jamie Dimon, were once Wall Street's darlings but have become embroiled in lengthy list of regulatory woes.
* The City watchdog yesterday confirmed that it has launched a formal investigation into "a number of firms" over suspected manipulation of the lightly regulated foreign exchange market.
The Financial Conduct Authority (FCA) said it was working with several regulators. The Swiss have already confirmed they are also involved.
The FCA's move is significant because a formal investigation is the first step in disciplinary proceedings against regulated firms.