Copper — Global Supply Tracker: Sep'Qtr soft ahead of strong supply growth into 2027 & 2028

The J.P. Morgan Global Metals and Mining Team covers 25 listed companies that report copper production from over 100 mines in 27 countries, accounting for ~54% of world copper supply. The September quarter saw production down 1.3% or 43kt, with output ~180kt below the Jun'25 quarter high; the team expects an aggressive bounce of ~150kt into the Dec'26 quarter, where Chile should recover from recent rain impacts. Our database shows sequential quarterly gains through 2027 and into 2028; 2027 output grows 987kt with 2028 growing another 1,089kt, following a 2026 decline of 261kt. Heading into 2027, Grasberg is the largest YoY contributor at +171kt, followed by Collahuasi at +151kt; 2028 growth is driven by Cobre Panama assuming a mid 2027 restart. At the global level, JPM's S/D model shows mine growth of 1.43Mt and 1.57Mt in 2027 and 2028 respectively, post only 530kt growth in 2026. Our listed company dataset accounts for ~70% of global supply growth in 2027, and the S/D balance shows a