JP Morgan has revealed it suffered a massive cyber attack on 76 million private and seven million business customers in the US.
The raid gathered account holders names and addresses but the bank said it did not involve critical information such as account and social security numbers.
It said in a filing with the Securities and Exchange Commission (SEC) that it had not seen any "unusual customer fraud related to this incident".
JP Morgan is the US's biggest bank. Earlier this year there were reports that Russia had hacked into its systems.
In August the bank said it was co-operating with law enforcement officials over this suspected incident.