Investors in resources stocks are taking a pessimistic view of trade tensions and are looking for reasons to worry about an ageing cycle, according to one of Australia's top resources fund managers.

After a 33-month upswing in fortunes for the mining and energy sectors, Colonial First State Global Asset Management's head of global resources Todd Warren said the market had become hyper-focused on the potential for trade sanctions between the US and China to derail the sector's return to health.