£21bn ‘Fat Finger’ mistake

I love the expression ‘fat finger’ mistake to describe a data entry error that nearly cost Swiss Bank UBS a whopping £21bn.

There are frantic claims that this error was not to do with data entry but was instead a ‘computer glitch’ on the Tokyo stock exchange, for which UBS has received an apology. The mistake arose when UBS found they had bought bonds worth 3,000,000,000,000 yen rather than a mere 30,000,000. Easy mistake to make.

But it didn’t cost £21bn to sort out. The trade was made ‘out of hours’ and in a desperate scramble it was cancelled before the deal was sealed. Fat finger errors do sometimes end in disaster. In one 2005 deal, a trader sold 610,000 shares for 1 yen each, rather than 1 share for 610,000 yen. That cost his employer nearly £300m.

So be careful next time you’re on eBay……