But in recent weeks trading geeks have started to talk about picoseconds in what is a truly mind-boggling concept: a picosecond is one trillionth of a second. Put another way, a picosecond is to one second what one second is to 31,700 years.

Why on Earth (which spins at a rate of 460 meters a second) is it necessary to trade so fast?

The answer is simple. Firms that trade super fast effectively put themselves at the front of the trading queue and have priority over other orders. This position gives them better information on the trading behaviour of other investors and allows them to react faster.

In a bull market, speed can ultimately make for beefy profits, but in a bear market these tiny fractions matter more than ever. The potential value of millisecond, or indeed a picosecond, was vividly demonstrated during a particularly bloody period on Black Friday, October 10, 2008, when the UK market plummeted at a hair-raising £250m a second.