US Copper Tariffs Finalized on June 30; COMEX Inventories Hit Record 650,000 Tons, Goldman Expects Copper May Breach $14,000 After Tariffs Take Effect

TradingKey - The countdown begins for the U.S. copper tariff decision. The U.S. Department of Commerce must submit its "Section 232" tariff investigation report to the White House by June 30 to make a final decision on whether to impose import tariffs on refined copper.

In July last year, the Trump administration announced a copper tariff plan, first implementing a 50% tariff on semi-finished copper and copper-intensive derivatives. Although refined copper was temporarily exempted, tariffs are scheduled to be phased in starting in 2027. By June 30, the U.S. Department of Commerce must submit an updated assessment report to make the final call on whether to implement the graduated tariff scheme for refined copper.

Copper is the largest and most essential metal for computing infrastructure. Over the past year, LME copper prices have risen by approximately 36% cumulatively. Once the refined copper tariff is implemented, it will not only directly drive up copper prices in the U.S. market but also reshape global copper trade flows.

[LME copper futures prices, Source: TradingView]

COMEX inventories surge to 650,000 tonnes, traders place early bets

The market has already moved ahead of time. Over the past year, U.S. traders have continuously transferred copper from the LME and other parts of the world to COMEX warehouses. COMEX copper inventories have climbed steadily from around 80,000 tonnes in February 2025 to 652,200 tonnes as of last week, hitting a record high.

COMEX copper prices have consistently traded at a premium to LME prices, with the core driver being market bets on the implementation of refined copper tariffs. Meanwhile, LME inventories have continued to draw down, with LME copper stocks falling to 352,100 tonnes last week, hitting a near three-month low. Amid this divergence, global copper inventories are rapidly concentrating in the U.S.

U.S. refined copper imports have also set new record highs. From January 2025 to May 2026, average monthly U.S. imports of unwrought refined copper stood at around 140,000 tonnes, nearly double the monthly average in 2024.

Goldman Sachs (GS) stated in a report released earlier this month that if the proposed tariffs take effect, copper prices could surge above $14,000 per tonne in the second half of 2026, triggering a new wave of stockpiling among U.S. buyers. Meanwhile, Goldman raised its year-end 2026 LME copper price forecast from $12,465 per tonne to $13,735 per tonne.

However, near-term copper prices are experiencing intense volatility. On June 24, Eastern Time, suppressed by hawkish Federal Reserve rhetoric and a strong U.S. dollar, LME three-month copper closed down $278, or 2.18%, at $13,371 per tonne; the most active COMEX copper contract plummeted 3.24% to settle at $5.9485 per pound, with an intraday trading range of $5.924 to $6.165 per pound. The market is locked in a tug-of-war ahead of the tariff decision, balanced between inventories and premiums driven up by the stockpiling wave on one side, and short-term selling pressure from macroeconomic headwinds on the other.

Industry insiders believe that if the tariffs are implemented as expected, U.S. copper prices could surge further, while regions outside the U.S. face deeper shortages due to the continuous outflow of supply.

Regardless of the decision on June 30, the global copper market has already been profoundly reshaped during this 18-month 'rehearsal.' COMEX inventories surged from 80,000 tonnes to 650,000 tonnes, U.S. refined copper imports doubled, and LME inventories outside the U.S. continued to shrink. After June 30, this reshaping will enter a new phase.

Computing power metals rally spreads; supply of tungsten, tin, tantalum, and indium tightens.

Beyond copper, supply tightness is also worsening for minor metals used in AI server manufacturing, such as tungsten, tin, tantalum, and indium, which are closely linked to the AI computing power supply chain.

[LME Tin Futures Prices, Source: TradingView]

Taking tin prices as an example, LME three-month tin futures are hovering around $50,000 per ton, up approximately 50% over the past year. In terms of tungsten concentrate, SMM pricing shows that as of June 26, the mainstream quote for 65% grade wolframite concentrate was concentrated around RMB 520,000 per ton, a cumulative increase of nearly threefold from its 2024 low. Prices for tantalum and indium also continue to rise.

The upward momentum is primarily driven by the rapid expansion of AI computing infrastructure. Tin demand has surged due to a spike in solder joints for Chiplet and HBM advanced packaging; tantalum is in high demand owing to an explosion in the usage of capacitors surrounding GPUs; and indium is propelled by explosive demand for 800G/1.6T optical modules and CPO (co-packaged optics) components.

At the same time, the resumption of production at Myanmar's tin mines has repeatedly fallen short of expectations since 2024, Indonesia has implemented strict controls on tin exports, and tantalum mining in the Democratic Republic of the Congo (DRC) has long been plagued by safety accidents and supply chain disruptions. Many institutions believe that under the dual impact of extremely low supply elasticity and the continuous expansion of AI capital expenditures, the supply-demand gap for these minor metals could persist until 2028.