In early afternoon trading in New York, copper for delivery in July touched a low of $2.62 a pound ($5,775 a tonne), down nearly 2% from Tuesday’s settlement. Copper is now trading more than 20% below levels seen this time last year, technically placing the bellwether metal in a bear market.

Frank Holmes, CEO of US Global Investors, a Texas-based investment company with a long track record in the gold and resource sector, points out in a blog post that the global gauge of manufacturing activity gave the worst reading in seven years in May.

The global Purchasing Managers Index (PMI) slid to 49.8 last month, signalling contraction in factory activity globally for the first time since 2012.

While technically in expansion mode (a reading above 50) US May PMI recorded its worst print since the aftermath of the 2008/09 global financial crisis.

China’s official PMI figures also slid below 50 last month with the employment sub-index tumbling to its lowest level in more than a decade. With the country consuming nearly half the world's copper, the price of the red metal is closely correlated with domestic factory conditions.

According to a new World Bank report, the value of global trade for 2019 has been revised down a full percentage point, to 2.6% — slightly below the pace observed during the 2015-16 trade slowdown and the weakest since the global financial crisis.