Goldman Sachs Cuts Copper Supply Forecast Amid Grasberg Mine Disruption

Goldman Sachs has downgraded its global copper mine supply forecast for 2025 and 2026 due to a disruption at Indonesia's Grasberg mine. The bank estimates a total loss of 525,000 metric tons of copper mine supply, reducing its 2025 forecast by 160,000 tons and its 2026 forecast by 200,000 tons. Goldman Sachs sees upside risks to its December 2025 copper price forecast of $9,700 a ton and reaffirmed its long-term bullish copper price outlook of $10,750 a ton by 2027.

Goldman Sachs has downgraded its global copper mine supply forecast for 2025 and 2026 following a disruption at Indonesia's Grasberg mine. The incident, which occurred on September 8, trapped workers underground due to heavy mud flow, prompting operator Freeport-McMoRan (FCX.N) to declare force majeure.

The bank estimates a total loss of 525,000 metric tons of copper mine supply as a result of the disruption, reducing its 2025 forecast by 160,000 tons and its 2026 forecast by 200,000 tons. Grasberg's production is now expected to fall by 250,000 to 260,000 tons in 2025 and by 270,000 tons in 2026.

Goldman Sachs sees upside risks to its December 2025 copper price forecast of $9,700 a ton, suggesting prices could settle in the $10,200-$10,500 range. The bank reaffirmed its long-term bullish copper price outlook of $10,750 a ton by 2027, citing challenges such as deeper mines, lower grades, and harder ore extraction, compounded by other disruptions this year at the Kamoa-Kakula and El Teniente mines.

The disruption shifted Goldman Sachs' 2025 global copper balance from a projected surplus of 105,000 tons to a deficit of 55,500 tons, though 2026 is expected to remain in a small surplus.

Goldman Sachs downgrades copper supply forecast after Grasberg mine disruption^[1] https://www.reuters.com/world/asia-pacific/goldman-sachs-downgrades-copper-supply-forecast-after-grasberg-mine-disruption-2025-09-25/