Did you know?

Click any word in a definition or example to find the entry for that word

fat finger syndrome

noun [uncountable]

accidentally pressing the wrong button when entering details on a computer keyboard




noun [countable]

'It is known as fat finger syndrome – the occasional tendency of stressed traders working in fast-moving electronic financial markets to press the wrong button on their keyboard and, in the process, lose their employer a mint …'

The Guardian 9th December 2005

'I am the fat-fingered fool who, overconfident of her online skills, recently tried to order one litre of goat's milk but ended up with five …'

The Telegraph 20th December 2005

'Many reasons have been given for London's victory in the race to host the 2012 Olympics. … it seems a technophobic Greek sports administrator with fat fingers may have been London's secret, albeit accidental, weapon.'

The Guardian 23rd December 2005

With the computer now an integral part of everyday life, but a good percentage of the computer-using population having no formal typing skills, the concept of frequently typing the wrong thing and having to correct it, is something we're all familiar with. It now seems we've got a description for this daily keyboard phenomenon: fat finger syndrome, and even as I write this article, I'm suffering from regular bouts of it.

in December 2005, fat finger syndrome was responsible for one of the most spectacular financial errors in history

If we're not just creating text, but using the keyboard to enter and submit details, fat finger syndrome can have significant repercussions. Some of us who enjoy the convenience of online supermarket shopping might already be familiar with fat finger syndrome. Sixteen cans of beans arrive at our door, and as we come to terms with the situation, we realise that we must have accidentally selected four multipacks of four cans, instead of four individual cans. Never mind, that'll keep us going for a while!

But the consequences of fat finger syndrome in financial contexts can be rather more serious. In December 2005, fat finger syndrome was responsible for one of the most spectacular financial errors in history, when a share dealer on the Tokyo stock exchange pressed the wrong button on his computer and landed his firm with a bill for £128,000,000. The Japanese trader meant to sell one share in a recruitment company for 600,000 yen – about £3000. But a typing error meant he sold 600,000 shares at a price of one yen, or around half a penny!

The significance of fat finger syndrome is not just restricted to financial transactions. In December 2005, it was alleged that London's victory in hosting the 2012 Olympics was partly attributable to a member of the International Olympic Committee pressing the wrong button during a crucial third-round vote.

One enterprising website offers a clever way to take advantage of fat fingers. If you're bidding on the auction site eBay, you can use fatfingers.com to search for bargains that few other people will find and bid for because of spelling mistakes in the descriptions of the articles that are on sale.

Background – fat finger syndrome, fat-fingered and fat-finger

The expression fat finger syndrome seems to have originated from the jargon of computer programming, where the term fat finger (also spelled fat-finger) is used as a transitive verb to describe the action of introducing a typing error which has very bad or unexpected results. Though the verb fat finger has spread to contexts other than computer programming, the related participle adjective fat-fingered is more common as a way of describing significant typing errors, or someone who makes them. Use of the expression fat fingers is also quite common, usually occurring as have fat fingers or with fat fingers, and an instance of fat finger syndrome is sometimes referred to as a fat finger.

by Kerry Maxwell, author of Brave New Words

This article was first published on 3rd April 2006.

Open Dictionary

Dunning-Kruger effect

the phenomenon by which an incompetent person is too incompetent to understand his own incompetence

add a word


A must for anyone with an interest in the changing face of language. The Macmillan Dictionary blog explores English as it is spoken around the world today.

global English and language change from our blog