Copper Tests Make-or-Break Support as Mine Supply Shrinks for the First Time Since 2017

Copper prices are probing a support level tied to April after global mine output declined 1.1% in the first half of 2026, while the metal has risen over 15% this year. Outages at Grasberg in Indonesia and Kamoa-Kakula in Congo erased about 600,000 tonnes of expected 2026 output, or roughly 2.5% of global mine supply, according to Sprott. Morgan Stanley's revised outlook sees mine supply flat or slightly lower this year, which would be the first annual decline since 2017. The shortage is in ore, not refined metal: International Copper Study Group data show a 131,000-tonne refined surplus in the first half, and miner Antofagasta sold Centinela ore at a negative $310-per-tonne treatment charge, effectively paying the buyer.