Copper Hit a Record. The Metal Did Not Disappear — It Moved.

Written 11 September 2026, on trading through the week to 10 September as reported by Bloomberg, CNN, MINING.COM and the South China Morning Post.

Copper set an all-time high on the London Metal Exchange this week, trading above $14,500 a tonne and touching a reported peak near $14,617. It has risen roughly 17 per cent this year.

The proximate cause is a tariff. The US Commerce Department has proposed a phased duty on imports of refined copper — 15 per cent from 1 January 2027, rising to 30 per cent the year after — and the market has spent months positioning for it.

What makes this rally unusual is that the metal has not disappeared. It has moved. Buyers pulling copper into the United States ahead of the duty have built COMEX inventories to a record — reported above 675,000 tonnes by late August, after 46 consecutive days of builds — while available LME stocks were drawn down to roughly 90,000 tonnes.

US imports of refined cathode in the first half of 2026 were close to 885,000 tonnes, more than double the same period two years earlier. The world has about as much copper as it did; a large share of it is now sitting in the wrong warehouses, and the price being quoted is the price of the copper that is still reachable.

Strip out the duty and the direction would still be up, more slowly. Mine supply has disappointed for several years while demand from three directions has not.

• •Data centres. The AI build-out is a copper story before it is a chip story — busbars, switchgear, transformers and the distribution to reach them.
• •Grid investment. Global grid spending is heading past half a trillion dollars a year, and a grid is largely copper and aluminium.
• •Electrification. Motors, chargers, pack busbars and cabling. An electric vehicle carries several times the copper of a combustion one.

Less than people expect, and it is worth being precise rather than alarming. Copper in a lithium pack is the busbars, the interconnects, the cabling and the anode current collector foil. It is real but it is not the bill of materials.

The cells dominate pack cost, and within a cell the cathode dominates. A copper move of this size is felt more in the things around the battery than in the battery — the charger, the wiring loom, the switchgear on a storage site, the transformer connecting it.

For a grid-scale storage project it lands squarely in the balance of plant, which is already the majority of the capital cost. Our walk through what a battery plant is made of besides batteries covers where that money goes.

• •The duty being settled — once the rate and date are fixed, the incentive to pre-position disappears and the inventory imbalance starts to unwind
• •The stockpiled US metal re-entering the exchange system, which would relieve LME tightness quickly
• •Demand disappointing, which on current grid and data-centre commitments looks the least likely of the three
• •New mine supply, which is the durable answer and the slowest — copper projects take the better part of a decade

Note the asymmetry: three of those four are about the tariff distortion resolving, not about the underlying balance loosening. A reader should expect the spike to deflate and the trend to persist.