Believe it or not, 2006 was a miserable year for many a commodities speculator. Hedge fund Amaranth springs to mind but those employing more mainstream strategies suffered too. The Goldman Sachs Commodities Index – the biggest of its kind – fell 15 per cent last year. The main reason is its high weighting to oil, where changes in the shape of the futures curve have caused the yield earned by rolling contracts to turn negative.

The boom that got going in 2002 is entering a new phase as the prices of individual commodities split in different directions rather than marching upwards in lock-step. Oil is unlikely to crash but the Organisation of the Petroleum Exporting Countries now defends a price floor. In some base metals, supply is tight but bellwethers such as copper have lost momentum. Precious metals are helped by a falling dollar but high prices curb jewellery demand. Droughts have caused shortages of agricultural staples. But recent enthusiasm for the likes of wheat also suggests that, several years into a bull run, speculators are ploughing the more esoteric end of the commodities field for yield.