Copper extended its rally to a fresh all-time high for a second straight session on Tuesday, September 8, as tight near-term supplies and expectations that the United States will impose tariffs on imports of refined metal continued to push prices higher.

How High Prices Climbed

The industrial metal rose for a fourth consecutive day on the London Metal Exchange (LME), touching an all-time peak of $14,617 a ton. Benchmark three-month copper futures had already surpassed the previous record of $14,527.50, set back in January, before climbing further. Copper has now rallied roughly 17% so far this year and 47% over the past 12 months.

Why Tariffs Are Driving Traders' Behavior

Traders have been shipping large volumes of refined copper into the United States, betting that President Trump will expand tariffs to cover imports of the metal. That anticipatory stockpiling has had a direct, measurable effect: Comex copper stocks — the US exchange where the metal is stored domestically — stood at a record 695,624 metric tons. Meanwhile, that same rush to secure US-bound supply has left inventories thinner everywhere else: stockpiles in warehouses monitored by the Shanghai Futures Exchange fell to their lowest level since January 2024.

A Market Signal Confirming the Squeeze

Spot copper continues trading at a premium to three-month futures — a market structure known as backwardation, which typically signals tight near-term physical supply, as buyers are willing to pay more for metal available right now rather than for future delivery.

The Supply Side of the Equation

Beyond the tariff-driven stockpiling, underlying mine production has genuinely weakened. Global copper mine output fell nearly 1% in the first half of 2026, while concentrate production declined 2.6%, according to industry reports — adding a structural supply constraint on top of the more immediate, tariff-driven disruption to trade flows.

The Longer-Term Demand Story

Underpinning the rally's broader durability is a persistent, longer-term mismatch between constrained mine supply and rapidly growing demand from data centers, renewable energy equipment, power grids, and electric vehicles. Copper's high electrical conductivity makes it a core input across all of these fast-growing sectors, and analysts have repeatedly flagged the metal's central role in the broader AI infrastructure buildout as a key structural demand driver likely to persist regardless of near-term tariff dynamics.

India Feels the Ripple Effects

The rally has spread to Indian markets as well: domestic copper futures on the Multi Commodity Exchange (MCX) jumped as much as 1.21%, or ₹16.8, to an intraday high of ₹1,403.50. Shares of state-owned Hindustan Copper Ltd surged more than 5% on the news, touching an intraday high of ₹537.35 on the BSE, as investors positioned for continued strength in copper-linked equities.

A Familiar Pattern From Earlier in the Cycle

This isn't the first time tariff-driven stockpiling has distorted global copper flows. A similar dynamic played out roughly a year earlier, when commodity traders approached Chilean producers to lock in annual US supply deals, some paying more than $500 per ton over benchmark LME prices, amid similar fears of incoming tariffs. At the time, Kostas Bintas, head of metals at Mercuria Energy Group, warned that a rush to ship metal into the US risked "draining the rest of the world's inventories," estimating more than 500,000 tons could arrive in the US in a single quarter — a warning that appears to have proven prescient given the current state of depleted non-US inventories.

What's Next

With Comex stockpiles at record highs domestically even as Shanghai inventories hit multi-year lows, the copper market's next moves will likely hinge on whether the Trump administration follows through on tariffs targeting refined copper imports, and how quickly global mine supply can respond to persistently tight conditions. For live copper price tracking, see the London Metal Exchange's copper pricing page.

With tariff speculation, thinning global inventories, and surging AI-driven demand all pulling in the same direction, copper's record-breaking run shows little sign of losing momentum for now.