The failure of gold-producing companies’ shares to echo the surging price of the yellow stuff they pull out of the ground has been a regular bone of contention for commodities fund managers, and a brief glance at the miners’ rapidly expanding operating margins since the beginning 2008 offers plenty of grist to the mill.

Craton Capital, a specialist natural resources fund manager, illustrates the point in the attached chart, which compares the operating costs of the gold-producing companies in its precious metals fund with the gold price since 1998.