- Lead. COMEX copper inventories have surged to a record 652,200 tonnes — more than eight times their pre-tariff level — as US buyers race to import refined copper ahead of a potential Section 232 tariff ruling that could price them out of global supply.
- Fact. The White House received the Commerce Department’s Section 232 refined copper report on June 30, 2026, and must now decide whether to impose phased tariffs: 15% from January 2027, rising to 30% in 2028.
- Stake. Goldman Sachs forecasts copper above $14,000 per tonne in the second half of 2026 if tariffs proceed, while LME inventories outside the United States have tightened as metal shifts across the Atlantic.
The United States copper market is experiencing one of its most acute inventory distortions on record. Exchange data compiled ahead of the US Independence Day break showed COMEX copper warehouses holding 652,200 tonnes as of July 3, 2026 — a figure that stood at roughly 80,000 tonnes before tariff anxiety took hold in early 2026. The 8x build-up is a direct consequence of front-loading by US manufacturers and traders who fear that a Section 232 ruling could sharply raise the cost of importing refined copper after the current year.
The tariff pipeline
The mechanism driving the stockpile is a two-stage US trade action. A 50% tariff on semi-finished copper imports — rods, tubes, and similar processed forms — took effect on April 6, 2026, prompting an initial scramble for refined cathode that sits outside that definition. The Commerce Department then completed its review of refined copper under Section 232 of the Trade Expansion Act, a national-security trade instrument, and transmitted its report to the White House on June 30. The White House now has 90 days to act, though a decision could come sooner. The proposal circulating in industry briefings suggests a phased structure: 15% from January 1, 2027, rising to 30% in 2028.
A 30% tariff on refined copper would, by Goldman Sachs’s modelling, push domestic US prices above $14,000 per tonne — roughly 40% above current London Metal Exchange benchmark levels. That premium would effectively wall off the US from the global copper market, forcing domestic consumers to pay a structurally elevated price while producers outside the US face a glut in non-US markets.
The global ripple
The inventory shift is already visible in LME data. As copper flows into COMEX warehouses, LME stocks outside the United States have tightened, creating regional price dislocations. Miners in Chile, Peru, and the Democratic Republic of Congo — which together account for more than half of global refined copper output — are watching the US tariff decision closely: a fully enclosed US market would require them to redirect large volumes to Asia and Europe, potentially depressing ex-US prices even as US domestic prices spike.
Copper futures on COMEX were trading near $6.10 per pound as of July 4, 2026, reflecting a market that has partially priced in tariff risk but is waiting for the White House’s formal ruling before moving to the next price level. Options markets show elevated implied volatility through the end of 2026, suggesting traders expect a sharp directional move once a decision is announced.
Industrial exposure
US manufacturers most exposed to the ruling include producers of electric motors, transformers, and power cable — sectors that cannot easily substitute aluminium for copper in high-voltage applications. The electric vehicle supply chain, which relies on copper-intensive wiring harnesses and charging infrastructure, faces a particularly acute impact: a 30% tariff would add an estimated $400 to $600 to the material cost of producing a mid-range EV battery pack’s copper components. Industry groups representing wire and cable manufacturers have filed formal comments opposing the tariff at the Commerce Department level, arguing that the domestic copper refining industry lacks the capacity to replace import volumes within the tariff’s phase-in timeline.