BIG DROP: Standard Chartered PLC saw 5.8 billion pounds ($9.1 billion) wiped off its market value Tuesday after the New York state regulator accused the U.K. bank of being involved in laundering money for Iran.

THE DISPUTE: The New York agency alleged that Standard Chartered conspired with Iranian clients to route nearly 60,000 U.S. dollar payments through Standard Chartered's New York branch after stripping identifying information. Standard Chartered said it "strongly rejects" the allegations.

BUT WAIT, THERE'S MORE: The storm surrounding Standard Chartered is the latest in a summer of scandals for the City of London, following shenanigans at Barclays, HSBC and the London office of JPMorgan.