Yes, there was a recent story about (yet another) Citi "fat finger" trade. The headlines mentioned things like "the trader ignored 700 error messages to put in

Yes, there was a recent story about (yet another) Citi "fat finger" trade. The headlines mentioned things like "the trader ignored 700 error messages to put in the trade", but listening to a podcast about it.. its more like awful systems that are always half broken is what ultimately lead to it. The real punchline was this - the trader confused a field for entering shares quantity for notional quantity, but due to some European markets being closed, the system had a weird fallback logic that it sets the value of shares to $1, so the confirmation back to the trader was.. the correct number of dollars he expected. So awful system designs lead to useless and numerous alerts, false confirmations, and ultimately huge errors.