Trading in shares in of five firms including BT and United Utilities were stopped due to excessive movement in their pricing.
The share values for each firm moved by over five per cent - shares in BT fell by over nine per cent while the value of stock belonging to United Utilities climbed by a similar amount.
Dr Giles Nelson, deputy chief technology officer at Progress Software, said: âWhile itâs commendable that the exchange detected and suspended trading in these stocks when the erroneous trades occurred, it should never have reached the exchange in the first place.
âYou have to ask the question, how on earth did they make it past the memberâs pre-trade risk system, if such a system was even in place or existed?â
âFat fingerâ errors are attributed to either human mistakes when the wrong figures have been input into a system or when a glitch in a trading algorithm occurs.
Circuit breaker technology was introduced to the US financial markets following the âflash crashâ of May 6th.
As much as $862 billion of equity value was lost in a 20 minute period.
By Jim Ottewill