US Tariff Fears Drive Copper Stockpile Rush
Traders are flooding American warehouses with refined copper to beat potential import tariffs, draining global inventories and pushing prices near all-time highs despite sufficient physical supply worldwide.
On the New York Commodity Exchange, copper for September delivery surged to a record US$6.7270 a pound, or approximately US$14,830 a metric ton. The price marks a nearly 4 percent premium over the London Metal Exchange (LME), where three-month contracts traded within striking distance of the US$14,527.50 all-time peak set in January.
Comex inventories have climbed for 46 consecutive days, reaching a record 675,185 metric tons. In July alone, more than 200,000 tons of copper landed at US ports—the largest monthly volume recorded in IHS Markit shipping data dating back to 2014.
The US imported 885,000 tons of refined copper cathodes in the first half of 2026, pacing to approach the record 1.64 million tons imported in 2025.
Tariff threat drives copper inflows
Uncertainty surrounding US trade policy continues to drive the rush.
The US Commerce Department was scheduled to deliver a copper market report to the White House by June 30.
The review will determine whether the administration proceeds with a 15 percent tariff on refined copper starting in January 2027, which could escalate to 30 percent by 2028.
With the looming escalating tariffs, the excess copper in US warehouses could serve as a critical domestic reserve rather than triggering a rapid destocking cycle.
This mass relocation of copper has altered the physical market balance. As reported by Reuters, CRU originally projected a 639,000-ton global copper surplus for 2026. Assuming the metal stockpiled in the US remains trapped, analysts now view the market as balanced at best.
Market participants expect the metal to remain stranded in the US, as the costs involved erase the financial incentive to re-export. Copper currently stored in Comex warehouses is already duty-paid.
Glencore (LSE:GLEN,OTCPL:GLCNF) CEO Gary Nagle noted prices will likely fall once a final tariff decision is announced, regardless of the exact duty rate, simply because it will eliminate current uncertainty.
“You’ll have these high stockpiles in the US, which over time will be drawn down for use … not to be exported again,” Nagle said in the company’s recent earnings call.
Mine outages, bottlenecks compound supply constraints
The tariff threat also builds on supply chain fractures already faced by the industry.
The closure of the Strait of Hormuz following the US-Israel war with Iran paralyzed shipments of sulfuric acid, a critical input for copper processing. Prices for the chemical surged to US$820 per metric ton in the Middle East and up to US$1,200 in import-dependent regions like Brazil.
Simultaneously, major mine disruptions constrain raw output. Chile, the world’s top producer, recorded…
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