Copper Shipments Surge into US Amid COMEX-LME Price Premium and Tariff Uncertainty

Copper shipments into the United States continued to surge as traders sought to capitalize on the price premium between the COMEX and London Metal Exchange (LME) markets ahead of a potential U.S. decision on refined copper import tariffs.

According to IHS Markit shipping data, more than 200,000 tonnes of refined copper arrived at U.S. ports during July, marking the highest monthly inflow in more than a decade. Combined inventories held on COMEX and LME facilities in the United States have now exceeded 740,000 tonnes, while additional material remains in storage at U.S. ports awaiting delivery.

The movement of metal into the U.S. has tightened availability in other key trading hubs. Market participants reported significant inventory declines at bonded warehouses in Shanghai, where stocks have fallen sharply since the beginning of the year as cargoes have been redirected to the U.S. to capture favorable arbitrage opportunities. The premium of COMEX copper over LME prices has remained well above historical norms, providing sufficient margin to offset transportation, insurance and warehousing costs.

The shift comes as the U.S. administration continues to evaluate potential tariffs on refined copper imports. While the timing and scope of any measures remain uncertain, the prospect of future trade restrictions has already reshaped global trade flows and inventory distribution.

The continued migration of copper inventories into the United States is tightening physical availability across international markets and supporting a firmer supply outlook outside North America. Any delay, revision or cancellation of proposed U.S. import tariffs could narrow the COMEX-LME price premium, potentially reversing some of the recent inventory movements and increasing short-term price volatility.