Copper has suffered its worst week since March, sliding as hopes of new United States tariffs on the metal faded and traders unwound bets built up on stockpiling ahead of a policy decision.

Front-month Comex copper for November delivery lost 24.05 cents a pound, or 3.72%, over the week to settle at $6.2180, Dow Jones market data showed. It was the largest weekly fall since the week ending 20 March 2026 and the lowest settlement since 9 July. The price is 8.61% below its record high of $6.8035, set on 9 September, but still 10.44% higher this year.

In London, three-month copper fell 3.2% to $13,883 a tonne on Tuesday 3 November, a three-month low, before recovering above $14,100 the next day. Research firm BMI said copper peaked at $14,875 a tonne on 10 September and still held above $14,000 on 5 November.

Tariff trade unwinds

The slide followed the Democrats' gains in the US midterm elections, which eased expectations of a tariff on refined copper. The prospect of a tariff had driven traders to stockpile metal in the United States, widening the premium of US prices over London and diverting hundreds of thousands of tonnes across the Atlantic. BMI said Comex copper stocks had risen 61.9% since the start of the year to 4 November.

Chinese premiums at records

While prices fell, physical supply stayed tight. Chinese buyers paid a record premium of more than $200 a tonne to import copper, the highest since Fastmarkets data began in 2017, and the premium has more than doubled in three months. Shanghai Metals Market said imported premiums kept hitting record highs through the week to 5 November as bonded-zone inventories fell to 23,900 tonnes.