Copper Hits a Record High as Traders Race to Beat Trump's Looming US Tariff

What happened

Copper set a fresh all-time high on September 7, with the London Metal Exchange (LME)'s three-month contract climbing as much as 0.8% to $14,533 a tonne, edging past the previous record of $14,527.50 a tonne set on January 29, 2026. The move extends a rally built almost entirely around a tariff that has not even been confirmed yet. US President Donald Trump's administration has been running a Section 232 national-security review of refined copper imports, with officials signalling a possible 15% tariff on refined copper cathode starting January 1, 2027, rising to 30% in 2028. That threat alone has been enough to pull metal physically into the United States: US refined copper imports hit a record 225,094 metric tons in July, and COMEX-registered inventories had climbed for 46 consecutive days to a record 675,185 metric tons by late August, according to Reuters. By early September, total US stockpiles across COMEX and private port warehouses were estimated at 695,000 to 766,000 short tons. Outside the US, the picture looks very different: combined LME and Shanghai Futures Exchange visible stocks had fallen below 250,000 tonnes, and CRU Group now says a market it once projected to run a 639,000-tonne surplus in 2026 looks, at best, balanced.

The details

The mechanics behind this rally are unusual because the trigger is a policy decision that has not actually happened. Traders don't need Washington to confirm a tariff on refined copper cathode to act on the possibility of one -- they only need to believe it's plausible enough to be worth hedging against. Because the proposed duty (15% from January 2027, rising to 30% in 2028) would apply to copper cathode arriving after it takes effect, the safest hedge is to get metal into the United States now, while it's still untaxed. That single incentive has pulled a record 225,094 metric tons of refined copper into US ports in July alone and pushed COMEX-registered inventories to a 46-day, 675,185-metric-tonne build. It's an arbitrage trade, not a demand signal: the copper isn't being bought because someone needs to use it tomorrow, it's being warehoused because it might cost 15% to 30% more to import next year.

That matters because it's happening on top of a supply side that already has real problems, not an imagined one. Chile, the world's top copper producer, posted a 9.4% year-over-year output decline in July. Indonesia's Gresik smelter has been offline since a boiler leak on August 8. Neither of those losses has anything to do with US tariff policy -- they're straightforward operational disruptions that would tighten the market with or without a stockpiling rush layered on top. When a genuine production shortfall coincides with a policy-driven scramble to divert whatever metal does exist toward one country, the two effects compound rather than offset each other.

That compounding is exactly what has forced CRU Group to revise its own outlook. The firm had projected a 639,000-tonne global surplus for 2026 -- comfortable, on paper. CRU's Robert Edwards now says that surplus effectively disappears once US-bound inventory is treated as unavailable to the rest of the world, calling the market "at best a balanced market," and warning that "if imports keep coming in as they have been, then it's going to look like a deficit market in reality." China, the world's largest copper-smelting nation, isn't in a position to plug that gap either -- Bank of China International's Amelia Fu points out that strong domestic demand is already absorbing much of China's own smelter output, leaving little spare capacity to redirect toward buyers elsewhere.

What keeps this from being a one-way bet is that the entire premium rests on uncertainty resolving in one specific direction. Macquarie's Alice Fox estimates that working through the copper already sitting in COMEX warehouses could take years once it's no longer needed as a tariff hedge -- meaning a large volume of metal could eventually flow back into global trade. Glencore CEO Gary Nagle has made a similar point from the producer side: a clear tariff announcement, even a confirmed one, is "likely to see prices fall," because it would remove the ambiguity that's currently driving pre-emptive buying. The record price, in other words, is being held up as much by not knowing what Washington will do as by any confirmed shortage of physical metal.

Why it matters

Indian buyers, wire and cable manufacturers, and traders who price copper off London Metal Exchange and COMEX benchmarks are exposed to a rally that has more to do with where metal is physically sitting than with how much of it actually exists worldwide -- meaning a US tariff decision in either direction, not just a fresh supply shock, could move prices sharply from here.