Record imports reshape U.S. inventories
More than 200,000 tonnes of refined copper arrived in the U.S. in July, the largest monthly import volume in at least 12 years. The shipments helped lift the country’s combined holdings in Comex warehouses, LME-registered stock and private port storage above 1 million tonnes. That total captures metal in several locations, but it doesn’t mean all of it is immediately available to buyers elsewhere: its location, ownership and intended use matter.
Importers are building those holdings as they position for a possible U.S. tariff on refined copper. The scale of the stockpile suggests that companies see a potential cost in waiting for clarity. It also means that expectations about trade policy are already affecting where metal sits, even though the proposed duties haven’t taken effect.
A widening gap between U.S. and global supply
While U.S. inventories are growing, metal available through London Metal Exchange warehouses is dwindling. Stocks have fallen for 42 consecutive sessions, the longest such run since 2014, to 204,975 tonnes. Nearly half of that inventory is already marked for withdrawal, a sign that the headline total overstates what may be readily accessible on the exchange.
The pressure shows up in copper’s pricing. Cash metal trades at a $434-per-tonne premium to the three-month contract, the widest spread since the 2021 squeeze that prompted exchange intervention. Buyers seeking prompt delivery have paid prices near $14,500 a tonne. That premium signals urgency in the nearby market: buyers are paying more to secure copper now than to arrange delivery later.
Here's the thing: a strong price for immediate delivery can coexist with uncertainty about supply over a longer horizon. The cash premium reflects the scarcity of metal available promptly, while the three-month contract also incorporates expectations about what supply and demand may look like later. This is more significant than it looks because the difference between those prices helps reveal where the market’s pressure is concentrated.
The U.S. stock build reflects uncertainty over President Trump’s proposed duties on refined copper: a 15% tariff from January 2027, rising to 30% in 2028. The Commerce Department’s June 30 deadline to deliver a recommendation passed without a public decision, leaving traders positioned for either outcome. The absence of a public recommendation hasn’t removed the policy risk; it’s extended the period in which traders have to weigh competing possibilities.
“The COMEX-LME spread has increasingly become a gauge of U.S. tariff expectations,” ING commodities strategist Ewa Manthey told CNBC. She said a wider premium continues to draw metal into the country. Societe Generale estimates the odds of the 15% tariff taking effect on schedule at just 14.6%, based on current spread pricing. That estimate is a market-based reading, not a settled outcome, and the spread can reflect other pressures on regional availability as well.
For importers, the calculation is difficult: bringing metal into the U.S. now may protect against a future duty, but it also ties up inventory while the policy path remains unclear. Similar stock-building episodes can make regional prices diverge when buyers anticipate different costs across markets. Here, the scale of the movement gives that positioning wider consequences for the supply available elsewhere.
Supply disruptions add to the squeeze
Tariff positioning is only part of the tightness outside the U.S. Congo’s ban on copper concentrate exports has led Chinese smelters to reduce operating rates. Storm damage took Antofagasta’s Los Pelambres mine offline; Codelco delayed its Andes Norte project to 2029; and Chilean national output remains near 5.5 million tonnes. Freeport’s Gresik smelter in Indonesia has been offline since August 8.
These events affect different links in the supply chain. A restriction on concentrate exports can limit the material available to smelters, while a mine outage or lower national output can constrain the supply of newly mined copper. A smelter outage adds a separate processing disruption. The details differ, but together they leave little near-term supply available to replenish LME warehouses.
That distinction matters because copper doesn’t move from a mine to a warehouse in one step. Production, processing, transport and delivery all shape how quickly metal can reach buyers, and delays at one stage can limit prompt availability even if supply exists elsewhere. The market’s immediate concern, then, isn’t simply how much copper is held in total. It’s how much can be delivered where buyers need it.
Copper miners have responded unevenly: Ivanhoe Mines has gained about 15% this month and First Quantum 12%, while Antofagasta has fallen roughly 3% since reducing its production guidance. Those share-price moves show that investors are distinguishing among companies rather than treating the sector as a single trade. Production guidance and the condition of individual assets can matter alongside the broader copper price.
What the inventory split could mean next
The market now has a geographic mismatch: U.S. inventories are swelling while accessible stocks elsewhere are shrinking. If you're working in this space, the distinction between total holdings and metal available for prompt delivery deserves close attention. A large stockpile in one region doesn’t automatically relieve a shortage in another, especially when the costs and timing of moving metal are part of the calculation.
A confirmed tariff could spur another round of imports and deepen the squeeze on London availability. A delay or a smaller duty could prompt some U.S.-held metal to return to the broader market. That said, a policy change wouldn’t guarantee an immediate reversal: companies would still have to decide whether moving that metal makes sense, and other supply disruptions would continue to shape the market.
(And this is the part most people overlook.) The tariff question is not the only driver of copper’s near-term availability. Mine, smelter and export disruptions have added pressure independently, so even a change in U.S. policy might not quickly erase the premium for prompt metal. The inventory split is a useful signal, but it doesn’t explain every source of tightness.
For now, the central uncertainty is whether the metal concentrated in U.S. warehouses stays there or becomes available to the wider market. The next tariff decision could influence that choice, while disruptions outside the U.S. may keep accessible supply tight in the meantime. No easy reset.