Meanwhile, the 'gasoline crack', the trading margin between the cost of a barrel of crude oil and the price of a barrel of gasoline (petrol), has risen above $30.

Trading margins were already off last year, from 8.9 per cent to 8.2 per cent.

It mirrored a similar performance at other investment banks which have all been struggling to cope with a lower activity and thinner trading margins as new regulations bite.

The change was because of an improvement in the estimate of trading margins at the banks that identified more financial service exports.

His business model was essentially discounted trading margins and a no-frills service -- he applied a 10% markup as opposed to the standard 25% from his competitors.