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.