Copper Holds Near Record as Yangshan Premium Hits Four-Year High on Chinese Restocking

LME three-month copper rose 1.2% to $14,250 a tonne on September 16 and extended the advance to $14,492 on September 17, a 1.82% daily gain. The rally is being driven by China, where the Yangshan premium, the standard gauge of appetite for imported copper, has climbed to its highest level in nearly four years. David Wilson, head of metals strategy at BNP Paribas, said Chinese buyers were taking advantage of the recent price dip to rebuild inventories, which is what lifted the import premium. Extreme mine-side tightness and very low Chinese domestic inventories are providing a floor under prices heading into the holiday period.

On the restocking side, several Chinese copper refineries are scheduled for planned maintenance between October and November, which could limit growth in refined metal availability, according to Shanghai Metals Market. Uncertainty also hangs over the pace of imported supplies because of port congestion in Shanghai. That physical tightness is only partly visible in exchange data: LME copper stocks rose 1.98% on September 17 to 254,150 tonnes, zinc inventories increased 1.30% to 112,675 tonnes and nickel stocks edged up 0.08% to 278,790 tonnes. Lead inventories fell 0.39% to 378,350 tonnes and aluminium stocks were unchanged at 243,600 tonnes.

The forward curve tells a more nuanced story. LME cash-to-three-month copper has swung from a backwardation of more than $500 a tonne in mid-August to a contango of roughly $86 by mid-September, signalling that prompt availability has improved materially. Part of that is supply response: Freeport Indonesia has resumed operations at its two Gresik smelters, with combined cathode output expected to approach 400,000 tonnes in 2026. PT Smelting holds around 342,000 tonnes a year of cathode capacity, and the Manyar smelter has restarted concentrate feeding with cathode expected in September. A curve in contango alongside a record-high import premium is an unusual combination, and it says logistics and policy are doing as much work as ore grades.

Mine supply is also being reshaped geopolitically. Democratic Republic of Congo copper exports reached a record 1,724,217 tonnes in the first half of 2026, up from 1.65 million tonnes a year earlier, with shipments to the United States and Europe roughly doubling after Kinshasa signed a strategic minerals partnership with Washington. State miner Gecamines has routed copper from large mines, including those linked to Chinese companies, to alternative markets through offtake arrangements with Mercuria and Glencore. Cobalt exports moved the other way, falling 6.4% to 41,140 tonnes under an export quota regime, and Kinshasa exported 151,200 tonnes of copper and cobalt concentrate in the half despite a ban, containing about 50,600 tonnes of copper.

The rest of the complex followed copper higher. On September 16 aluminium rose 0.8% to $3,276 a tonne, nickel gained 1.3% to $16,150, tin added 1.2% to $52,700 and lead was up 0.5% to $1,882, while zinc fell 0.6% to $3,810. By September 17 zinc had rebounded 1.81% to $3,882 and lead 1.30% to $1,910, with aluminium up 0.99% at $3,302 and nickel 0.76% at $16,290. Traders attributed the broad strength to relief after the Federal Reserve rate increase, a softer dollar and renewed Chinese buying. Aluminium carries a separate risk: US tariffs on some Canadian products have reached a combined 100%, and Canada supplied almost half of US aluminium-product imports last year, putting more than $428.9 million of annual Canadian exports in play.