U.S. Copper Stockpiles Surpass 1 Million Tonnes, Record High; COMEX Inventories Break Above 650,000 Tonnes

Global visible inventories at the three major exchanges total about 1.11 million tonnes, with the U.S. alone locking in over 1 million tonnes—equivalent to half a year of its domestic consumption.

Core Facts

Global visible inventories at the three major exchanges total about 1.11 million tonnes, with the U.S. alone locking in over 1 million tonnes—equivalent to half a year of its domestic consumption. COMEX copper inventories have nearly doubled from about 340,000 short tons at the end of last year, surging from 84,000 tonnes to 650,000 tonnes in 18 months. The massive inflow of copper into the U.S. is driven by tariff expectations. In February 2025, the U.S. initiated a Section 232 investigation, with a 50% tariff already imposed on copper semis, while refined copper is temporarily exempt. The plan is to levy 15% from 2027 and raise it to 30% in 2028.

Policy and Trade

The market expects cathode copper arriving in the U.S. before 2027 to be exempt from the new tariffs. The arbitrage spread once reached USD 600 per tonne, yielding a net profit of over USD 200 per tonne after costs. U.S. stockpiling has left other regions with tight inventories. LME copper inventories have fallen to about 240,000 tonnes, SHFE inventories to about 69,000 tonnes, and LME deliverable warrant stocks once stood at only 94,000 tonnes.