Shares in HSBC jumped nearly 10 per cent in minutes yesterday in what traders said looked like a costly mistake.

The bank jumped from around 630p to 688p, prompting an automatic suspension of the shares for five minutes. When they restarted they fell back to their previous level.

One trader said: “This looks like a fat finger; it’s a complete error. It looks like someone has taken a hit of around £400,000.”

The London Stock Exchange said it was investigating the situation.

The move in HSBC briefly pushed the FTSE 100 into positive territory. Earlier an 11 per cent drop in drinks giant Diageo was also put down to a "fat-finger" mistake when a trader accidentally inputs the wrong price for a buy or sell order. – (Copyright: Guardian News & Media 2014)