US warehouses hold 70% of LME copper as China pays premiums

Some 223,300 tonnes of London Metal Exchange copper, or 70.1% of the exchange's stocks, sat in US warehouses, the highest American share since March 2019, ADM Investor Services said on Thursday, even as Chinese import premiums stayed elevated, a contrast the firm said shows that rising exchange inventories do not mean the metal is readily available elsewhere.

Comex inventories reached a record 732,315 tonnes, ADMIS said. Reuters put the Comex record at 731,428 tonnes and said inventories in LME warehouses in the United States were at their highest in more than a decade. Official LME copper stocks stood at 312,250 tonnes on Wednesday, up 2,600 tonnes, according to data compiled by Westmetall.

US share of LME copper stocks at two readings — 62.1% on Oct. 22 and 70.1% on Nov. 5 — against the Yangshan warrant weekly average. Comex stocks are labeled at those dates; the Nov. 5 label uses ADMIS's 732,315 tonnes. Sources: ADMIS; Reuters via Business Recorder; Shanghai Metals Market; Westmetall | copperstocks.org

As the Comex premium over LME prices narrowed, ADMIS said, more metal moved into US-based LME warehouses, where it can be stored without first clearing customs. Shanghai Metals Market put the LME-Comex spread at about -$71.81 a tonne as of Wednesday and said Comex copper had shifted from a premium to a discount against the LME contract, reducing the incentive to send more cathode to the United States. When tariff expectations were stronger, SMM said, that spread had widened to several hundred dollars a tonne, drawing large volumes of cathode into the US and leaving inventories there out of balance with stocks in other regions.

China's physical market shows the other side of that split. ADMIS said the Yangshan import premium rose to $210 a tonne, matching its 2013 record. Shanghai Metals Market put Thursday's average Yangshan warrant premium at $210 a tonne, in a range of $195 to $225, and the week's average at $204. SMM said imported copper premiums continued to hit record highs, citing tight supply, low domestic cathode inventories and limited arrivals at the ports.

Bonded-zone copper inventories in China fell 2,900 tonnes from Oct. 29 to 23,900 tonnes as of Thursday, SMM said, including a 2,800-tonne decline in the Shanghai bonded zone to 21,400 tonnes.

Still arriving

The United States imported 194,284 tonnes of refined copper and copper alloys in September, down 3.1% from 200,519 tonnes in August and below July's record of 225,094 tonnes, official data showed, Reuters reported. Shipments were still almost double the 102,279 tonnes imported in September 2025.

Over the first nine months of this year, US imports reached 1.52 million tonnes, up 17% from a year earlier. The United States imported a record 1.64 million tonnes last year. Chile, the Democratic Republic of Congo and South Korea were the three largest suppliers in September.

The Trump administration has proposed a 15% tariff on refined copper imports from 2027 but has yet to confirm it will go ahead with the levy, Reuters reported. SMM said that as the expected date has approached without a decision, the market has been reassessing the chance the duty is delayed or cancelled, a shift already visible in the collapse of that spread.

Whether the metal already stacked in American warehouses is released back onto world markets still depends on that refined-tariff call, which remains with the White House rather than with Congress.

SMM said imported cargoes are expected to arrive in China gradually after the middle to late part of this month to replenish supply, though downstream buyers remain wary of the high premiums for forward shipments. Traders are hoping for clarity on the tariff now that the US midterm elections are over, Reuters reported.

(With files from Reuters)