For most of the last decade the scarce thing in copper was smelting capacity, and Chinese smelters charged miners handsomely for it. That has inverted. The 2026 benchmark treatment and refining charge — the fee deducted for converting concentrate into refined metal — settled at zero dollars a tonne, the lowest on record. In the spot market the fee turned negative, reaching minus $126.80 a tonne at the end of June. Smelters are paying for the privilege of processing ore. The binding constraint has moved to the mine, which is where the margin in this story is earned.

The squeeze got worse in August. The Democratic Republic of Congo banned concentrate exports on 6 August; rain shut Antofagasta's Los Pelambres and forced roughly a 5% cut to its output guidance; London Metal Exchange stocks fell for a 42nd straight day to 204,975 tonnes. The premium for metal today over metal in three months reached $478 a tonne, the widest since the 2021 squeeze.

Teck got more profitable and cheaper at once

Teck Resources sold its steelmaking coal business and now earns its living from copper, with zinc attached. June-quarter revenue was C$3.61bn, up 78% on a year earlier. Gross margin reached 44.3%, against 23.3% in the same quarter of 2025. Copper output rose 25%, and net cash unit costs fell 19% to $1.64 a pound despite an energy headwind of about 7 cents. Copper generated roughly 84% of segment gross profit before depreciation. The balance sheet ended the quarter in a net cash position of $1.2bn.

The unusual part is the price. Teck changes hands at 9.0x trailing gross profit — down from about 10.8x three months ago and 10.6x a year ago — because gross profit grew faster than the shares. Forward earnings are 10.9x against 17.8x trailing. Management warned that mill downtime and planned grade reduction at Highland Valley will keep full-year copper below the midpoint of the 455–530kt guidance range, and the $53bn all-stock merger into Anglo American still awaits Chinese and South Korean clearance.

Hudbay re-rated ahead of its own numbers

Hudbay Minerals mines copper concentrate at Constancia in Peru and in Manitoba, and is trying to fund Copper World in Arizona. Gold byproduct credits equal to 38% of gross revenue pushed its consolidated cash cost to minus $0.40 a pound. But growth is fading at the edges: revenue rose 21.4% year over year in the June quarter after 27.3% in March, and gross margin slipped to 41.0% from 48.6% sequentially. The Copper World feasibility study has slipped to early in the fourth quarter, with management conceding capital costs will exceed the 2023 study.

Against that, the shares now cost 12.9x trailing gross profit, roughly double the 6x of a year ago. Forward earnings, at 18.7x, sit above the trailing 16.7x — consensus expects less next year than the trailing figure shows, which a one-off gain in late 2025 flattered.

Rio Tinto is not the iron-ore control

Rio Tinto was supposed to be the diversified counterweight. It isn't. First-half copper earnings before interest, tax, depreciation and amortization rose 84% to $5.7bn, 36% of the group, while iron ore was flat at $6.8bn despite the strongest first-half Pilbara output since 2018. Rio is also adding to the supply pressing on iron ore, with Simandou ramping into a market forecast to average about $95 a tonne. Its shares cost 9.88x trailing gross profit, above pure-play Teck.

The AI link is downstream, not disclosed

Estimates of 27 to 33 tonnes of copper per megawatt of data-center capacity, and about 475,000 tonnes of demand in 2026, are forecasts, not shipments. The hard corroboration sits one rung down the chain: cable maker Prysmian raised 2026 free cash flow guidance to €1.65–1.75bn on grid and data-center orders. Rio has signed Amazon Web Services as first buyer of copper from its Nuton bioleaching venture, for US data-center components — a disclosed offtake rather than an inference.

All three moved into confirmed uptrends within days of each other in mid-August, their 50-day averages crossing above their 200-day. But the month's burst is broad mining beta: BHP, iron-ore weighted, rose 16.1% over 30 days against Teck's 20.2%. Only over three months does copper separate — Freeport up 13.0% and Southern Copper 12.4%, against Alcoa down 19.2% and Vale down 12.8%.

The setup

Where it stands — A physical concentrate shortage is lifting all three, but only Teck's earnings have outrun its share price. Would confirm — Teck full-year copper output landing inside 455–530kt with net cash unit costs at or below $1.64/lb. Would invalidate — Spot treatment charges returning above zero, or LME stocks rebuilding past 300,000 tonnes. Watch next — Hudbay's Copper World feasibility study and capital estimate, due early in the fourth quarter of 2026. Valuation — Teck 9.0x trailing gross profit and 5.9x forward, versus Hudbay 12.9x and Rio Tinto 9.88x.