New York, March 18, 2026, 13:19 EDT
Rio Tinto plc’s U.S. shares slipped 1.1% to $88.79 by midday Wednesday. Traders digested fresh progress at the company’s Resolution Copper project in Arizona, but softer copper prices and another wave of inflation nerves kept a lid on the stock, which hit an intraday peak of $90.80.
The market’s shrug is notable as Rio pushes copper to the front, even though iron ore remains the main profit engine. Back in February, the miner posted 2025 underlying earnings—excluding one-offs—of $10.87 billion. Copper chipped in roughly 30% of group earnings, but iron ore still held close to 60%.
On Monday, Rio announced it now controls the 2,400 acres in Arizona required for Resolution—a copper deposit Reuters says contains over 40 billion pounds of the metal. The project has already cost Rio and its 45%-owned partner BHP upwards of $2 billion. Even so, Rio hasn’t provided a timeline for when output could start.
Rio expects to spend roughly $500 million over the coming two years on drilling, early-stage work, and community initiatives, a phase that brings about 100 jobs. Katie Jackson, Rio Tinto Copper’s chief executive, described the land swap as a “significant milestone,” adding it could lay the groundwork for “a stronger copper business.” The miner says Resolution could one day supply as much as 25% of U.S. copper demand and deliver $1 billion annually to Arizona’s economy. Rio Tinto
Miners struggled on Wednesday. Copper slid around 2% based on Reuters/LSEG figures, with Brent crude surging close to 5%. The FTSE 100 slipped nearly 0.9%. Also, U.S. producer prices jumped 0.7% in February—more than double the 0.3% economists had expected in a Reuters poll. That’s stirred up concerns: pricier oil and stubborn inflation might mean higher rates stick around.
Rio’s mood has been subdued since its annual results. London-listed shares slid 3.4% when the numbers dropped in February. Andy Forster at Argo Investments called them “not as impressive as BHP”—pointing to weaker iron ore pricing, higher Pilbara expenses, and unresolved doubts after the failed Glencore merger talks. Reuters
Even with the Arizona win, cash flow isn’t on the horizon yet. Rio flagged the need for more drilling before it can estimate when production might start. State permits also remain in limbo. Meanwhile, AP noted that a group of Apache women has petitioned the U.S. Supreme Court to step in after the federal land transfer.
If it goes ahead, Resolution could give Rio’s copper portfolio a lift just as BHP steps up its focus on the metal, with major miners still struggling to pull off sizable transactions. The stock’s move on Wednesday hinted at backing for the approach, though investors aren’t rushing to assign much value to a project that remains far from coming online.
