The US Megabank Citigroup Must Pay Another Million Dollar Fine Due to a Significant Error in Stock Sales.

A Citigroup trader caused brief turbulence at multiple stock exchanges in May 2022 due to a mistaken input. Instead of selling securities worth $58 million, the trader accidentally placed a sell order for a stock package worth $444 billion. Although the bank’s control systems prevented the majority of the unintended sales, shares worth approximately $1.4 billion were still sold on European exchanges before the trader noticed the mistake and canceled the order.

The incident led to a five-minute sell-off in the OMX Stockholm 30 stock index and caused chaos in the stock markets from Paris to Warsaw. According to Bloomberg, approximately 300 billion euros in market value were temporarily wiped out.

Citigroup Global Markets Europe AG, headquartered in Frankfurt, outsourced the monitoring and management of computer trading to London, where the costly mistake occurred. However, BaFin determined that the bank remains responsible for the proper design of the trading system. This system failed to recognize the trader's error and transmitted erroneous orders, ultimately leading to a market disruption.

Already in May, the British financial market regulator FCA and the financial services regulator PRA had fined Citigroup a total of around 61.6 million British pounds (approximately 72 million euros).

In trading on the New York Stock Exchange, Citigroup's stock temporarily fell by 0.15 percent to $60.69.