As a ex. IB Delta One Trader, this sort of thing shouldnt be possible. It is more a reflection of the fact Citi's systems dont have (any? or sufficient) fat fin

As a ex. IB Delta One Trader, this sort of thing shouldnt be possible. It is more a reflection of the fact Citi's systems dont have (any? or sufficient) fat finger checks (or liquidity impact checks) pre execution. Trade entry errors are a given when you are probably doing 50-500+ trades a day, its the processes and procedures in place to mitigate them that are important. It is also telling from a cultural perspective that the trader in question is on leave - rather than someone from management who allowed poor risk management/technology design/governance to seep into such a critical system. Citi has a poor reputation on the street for systems and people - this just perpetuates that status.