COMEX Copper Stockpiles Hit a Record 706,818 Tons. The Tariff That Built Them Still Isn't Official.

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Copper traded at 654.5 cents a pound on the London Metal Exchange Monday afternoon, a 0.52% gain on the day. That's a small move on its own. The bigger number sits underneath it: 2026's year-to-date average price of 610.0 cents a pound is running 40.53% above last year's average of 434.1 cents, according to exchange data.

Most of that gain has little to do with how much copper the world is actually consuming right now. It has to do with where the metal is sitting. COMEX warehouses in New York held 706,818 tons of registered copper on Monday, the most on record and still climbing. The London Metal Exchange, traditionally the market's deepest pool, held 244,900 tons after shedding another 3,750 tons, a 1.51% drop, in a single session. Shanghai's exchange is frozen at 38,744 tons this week because China is closed for its Golden Week holiday, but that number has been sliding for months regardless.

What Changed

The copper market spent much of 2026 pricing in a tariff that still doesn't exist. In August 2025, the Trump administration placed a 50% Section 232 tariff on semi-finished copper products, items like rod, bar, sheet and cable, while carving out an exemption for refined cathode copper, the raw form later turned into wire and components. Commerce Secretary Howard Lutnick delivered a recommendation on refined copper by a June 30, 2026 deadline, with the administration weighing a 15% duty starting January 1, 2027 that would climb to 30% in 2028.

No decision followed. A second, harder deadline tied to the Commerce Department's 90-day Section 232 review window came and went on September 28 with still no announcement from the White House. Traders are now treating that silence as a soft no, at least for now, even though officials say they continue evaluating options. Reporting in September tied the delay to concern about raising costs for automakers, electrical equipment makers and construction firms just as the administration argues, ahead of November's midterm elections, that its policies are lowering prices rather than raising them.

Why It Matters

Traders didn't wait for Washington to decide, at least not at first. Since February, American buyers stockpiled refined copper ahead of a tariff that might never arrive, pulling metal out of London and Shanghai and routing it toward COMEX-registered warehouses instead. The COMEX price traded at nearly a $600-a-ton premium over the LME in late July. That premium has since collapsed to somewhere between $120 and $230 a ton, a sign that conviction a tariff is actually coming has faded even as the physical stockpile built on top of it keeps growing.

Underneath the trade-policy noise sits a real demand story too. Only two copper smelters still operate in the United States, and the country imports roughly half its annual copper needs; refined copper imports have jumped 16-fold since 2015 even as domestic mine production slipped 20%. S&P Global, separately, expects global copper demand to grow 50% by 2040, pointing to AI infrastructure and defense spending as the two biggest drivers. Data centers consume enormous amounts of copper wiring and busbar, which is part of why Texas's data center buildout, where developers are requesting far more power than the grid has ever delivered, belongs in the same conversation as a metal most people associate with electricians and plumbing.

What to Watch Next

Where copper goes from here depends most on whether Washington ever makes the call it's been deferring since June. Two deadlines have now passed without a decision, and the longer that continues, the more likely the remaining COMEX premium keeps eroding toward zero, potentially leaving the record stockpile sitting in New York with less reason to exist. China's physical demand should become clearer once the Shanghai exchange reopens October 8 after its holiday closure. The Federal Reserve is also part of the picture: softer September payrolls data has already pushed traders toward betting on further rate cuts, and easier policy tends to support industrial metals alongside gold and silver.

The Pulse24 Take

The headline price is telling you less than it looks like it is. Most of copper's 2026 gain reflects a trade-policy bet that's already showing cracks, not a verdict on global industrial demand, and that distinction matters for anyone using the metal as a read on the broader economy. The more useful signal isn't the London price or the New York price in isolation. It's the gap between them, and that gap has been shrinking for exactly the reason you'd expect: two deadlines have now passed with Washington saying nothing at all.

If the administration lets this keep slipping into next year, don't be surprised if COMEX's record stockpile turns from a hedge into an overhang. The AI-driven demand story underneath all this looks durable. The tariff-driven price premium that pulled all that metal to New York in the first place is already fading.