Global copper mine supply fell 1.1% in the first half of 2026, and outages at two of the world's big operations did most of the damage. Grasberg in Indonesia and Kamoa-Kakula in Congo erased roughly 600,000 tonnes of expected 2026 output — about 2.5% of global mine supply, according to Sprott. Copper prices are up more than 15% this year, and the squeeze is arriving just as AI data-center builders start asking for a lot more of the metal.
The math on a 1-gigawatt campus
Industrial Info Resources figures a single 1-gigawatt AI data center campus can require up to 50,000 tonnes of copper. That's a lot of metal for one building. The cost, though, is almost a rounding error: copper makes up under 0.5% of a data center's budget. The real risk isn't price. It's getting transformers and cables on schedule. Builders who can't source the copper can't energize the campus, and a project that slips a quarter is far more expensive than a slightly higher metal bill.
Morgan Stanley sees mine supply flat or slightly lower this year. If that holds, it would be the first annual decline since 2017. That's not a supply collapse. It's a supply that isn't keeping up with demand that keeps getting revised upward.
The long grind from discovery to production
S&P Global projects 2040 copper demand at 42 million tonnes, leaving a supply shortfall of roughly 10 million tonnes. The number that matters more is 17. That's the average time it takes to bring a copper discovery into production, per an S&P Global study. Even a wave of new discoveries today wouldn't arrive in time to close a gap that opens in the 2040s.
There's an odd wrinkle in the refined market. International Copper Study Group data show a 131,000-tonne refined copper surplus in the first half of 2026, with smelters leaning on scrap. Antofagasta sold Centinela ore at a treatment charge of minus $310 per tonne — effectively paying the buyer to take it. Negative treatment charges are a smelter problem, not a consumer one. They signal concentrate is tight even as refined metal looks ample.
Warehouses are full, and that's the point
Comex warehouse copper stocks hit a record near 700,000 tonnes in September. Traders are front-running a proposed 15% tariff on refined imports due to take effect in 2027. That's metal sitting in a warehouse to dodge a tax, not metal headed to a job site. When the tariff question resolves, some of that stock will move — and the market will find out how much of the surplus was real demand and how much was positioning.
Fifth test of the April trendline
On the chart, copper is testing its ascending April support trendline for the fifth time. The line held on four earlier tests in June, July, September, and early October. Just overhead sits a horizontal resistance zone near $6.70 per pound that has capped rallies since May. A confirmed breakout could target $6.95, the September record high. If the April trendline breaks instead, the 0.382 Fibonacci retracement near $6.31 may act as the next floor. The Relative Strength Index hovers near 50 — neutral, neither stretched nor washed out.
For context, copper is up about 33% year-over-year. Bitcoin's spot price sits near $81,700, roughly 25% lower. The industrial metal and the digital one have parted ways this year.
The next thing to watch is whether that fifth trendline test holds like the first four. The tariff decision and the pace of data-center construction will decide whether the breakout or the breakdown gets the final word.
