Citigroup fined over ‘fat finger’ error that led to £1.1bn of mistaken orders

UK regulators fine bank 61.6m over 2022 trader blunder that prompted flash crash in European stocks

Citigroup has been fined 61.6m by financial regulators after its internal systems failed to prevent a fat-fingered banker causing a flash crash by erroneously placing more than 1bn of orders.

The trader had intended to sell equities to the value of $58m (46m) on 2 May 2022. However, the banker made an inputting error while entering the transaction into Citigroup's order management system, so a giant equities basket of $444bn was created - and $1.4bn was then sold into the market.