Copper prices brushed the $4 mark over the third week of August, their lowest point since February. They have since bounced back to around $4.2, though they remain off around 10% from May highs.

As is nearly always the case with industrial metals, copper prices have been a factor of demand from China, where a Delta outbreak over the summer – now contained – is beginning to reflect in data releases. To date none is more important than the Caixin China purchasing managers index, which signaled a contraction in manufacturing with its 49.2 reading in August, down from 50.3 in July.