New York

AFTER months of battering from tumbling crude prices, commodity index investors may soon have another reason to consider leaving the oil market: contango.

For the first time since January, the US West Texas Intermediate (WTI) crude oil futures market is poised to flip into contango, a structure in which prompt prices are below longer-dated contracts, typically signalling a weaker market. Outright oil prices have already tumbled about 25 per cent since summer.