DURING the commodity “supercycle”, prices largely marched up and down in unison, fuelled by the strength (or weakness) of demand in China. Since last year commodities have again been on a tear, but for more idiosyncratic reasons. In the case of copper, strikes and supply disruptions in two of the world’s largest mines have helped push prices this week to their highest level in 20 months. This fits into a narrative of longer-term potential supply shortages that has investors licking their lips over prospects for the red metal.
A strike that began on February 9th at Escondida in Chile, the world’s largest copper mine, has been compounded by a dispute between operators of Grasberg, another huge copper mine, located in the Indonesian province of Papua, and the government. That led to a halt in copper-concentrate production there, too, on February 10th. The two account for 9% of mined copper supply.