Coppers 6.69 All-Time Record|The Sulfur Shock Iran Left Off the Front Page?

A War Story That Never Mentioned Copper

On Wednesday, while Wall Street's attention was fixed on a new Fed chair and a presidential summit in Beijing, a commodity that wires every EV, data center, and power grid just hit a price the US market has never seen. Comex copper surged to $6.69 per pound — a record. The S&P 500 and Nasdaq closed at fresh highs. The 10-year Treasury yield pressed toward 4.5%, its highest in ten months. Producer prices rose 6% year-over-year in April, the sharpest gain since December 2022. That was the day's loudest number, and it was copper's quietest.

The Iran war narrative has centered on oil. The Strait of Hormuz, crude at $103 a barrel on WTI, tankers stranded, energy inflation feeding the PPI print that rocked bond markets. That framing is not wrong. It just stops one step too early. Because the strait that stopped oil tankers also stopped something else, and that something else is now moving through the supply chain in a way that oil prices cannot capture.

The Nasdaq's semiconductor rebound carried most of the session's optimism. Jensen Huang, Nvidia's CEO, boarded Air Force One alongside Trump's delegation to Beijing, and markets read that as a signal that chip export restrictions to China could ease. The S&P 500 added fractionally while the Dow lagged. Kevin Warsh won Senate confirmation as Federal Reserve chair in a 54-45 vote — the most partisan confirmation of any Fed chair in history — taking the seat from Jerome Powell effective Friday. Markets noted it, then moved on. Copper did not move on.

Why a War in Iran Is a Copper Supply Crisis in Chile and Peru

The mechanism begins with sulfur. The Gulf region — specifically Persian Gulf refineries and petrochemical plants — is one of the world's largest suppliers of sulfuric acid, and sulfuric acid is how copper ore becomes copper metal. Roughly a fifth of global mined copper output depends on sulfuric acid as a processing input. When the Hormuz chokepoint effectively closed in late February, sulfur shipments from the Gulf collapsed. Analysts now estimate that the disruption could affect up to 4.8 million tonnes of annual copper production — more than 20% of global supply.

That consequence is not showing up in oil headlines because oil is the direct output of the Gulf. Sulfur is a byproduct, and byproducts move quietly until they don't. In China, the world's largest copper consumer, refined copper output fell 3% in April and may fall further in May, according to Beijing Antaike Information. The supply shock is no longer upstream — it has crossed into refined metal. The LME copper price in London rose to nearly $14,200 per tonne, within $300 of its January all-time high. But the US Comex price, which already carried a tariff premium, broke to a new record outright: $6.69, up 2.4% on the day and more than 10% year-to-date.

A second catalyst is layered underneath. The US Commerce Department is due to release an updated report on domestic copper market conditions by June 30 — a report that could recommend broad tariffs on refined copper imports. Traders have already begun front-running that decision. Arbitrage flows are reopening between London and New York. US copper inventories are rising, not because demand is weak, but because traders are pulling metal into the country ahead of a potential tariff wall. Price and inventory are both rising simultaneously — a configuration that signals positioning, not consumption.

What that configuration does not yet tell us is whether the supply disruption is temporary or structural. The Hormuz situation has not resolved. Iran is now processing tanker passage through the strait on a case-by-case basis, suggesting operational control has not been relinquished. Each day that sulfuric acid shipments remain interrupted is another day of processing capacity deferred at mines that cannot simply substitute inputs. The copper market is now betting that this does not resolve quickly — but that bet has a number attached to it.

The $14,500 Test and the Condition That Breaks It

The LME all-time high of $14,500 per tonne, set in January, is the number that now defines the copper trade's next phase. If Comex continues to lead and the London price closes that $300 gap, the narrative shifts from a tariff-driven US premium to a genuinely global supply shortage — and the capital implications are different. A tariff premium can compress when policy shifts. A physical supply shortage does not compress until mines restore throughput, and throughput depends on sulfuric acid, and sulfuric acid depends on the Hormuz passage.

The historical parallel that traders are reaching for is the 2021-2022 period, when pandemic-era supply chain disruptions drove copper to then-record levels above $10,000 on the LME. In that episode, prices eventually corrected sharply as Chinese demand softened and supply chains normalized faster than expected. The bears in the current trade are running a version of that scenario: Iran conflict de-escalates, Hormuz re-opens, Gulf sulfur flows resume, the tariff report in June disappoints the hawks, and Comex premium compresses back toward London.

That scenario has a specific test point. If the June 30 Commerce Department report recommends tariffs below the market's current pricing assumption, or if diplomatic progress at the Trump-Xi summit in Beijing produces movement on Iran — China is Iran's largest oil customer and has a direct incentive to see the strait reopen — then the front-running trade in US copper unwinds. The Comex-LME spread, currently elevated, would compress. That compression is the early warning signal to watch, not the absolute price level.

The case for continuation rests on the sulfuric acid constraint holding independent of tariff outcomes. Even if the Commerce report disappoints and the spread compresses, the physical supply problem at mines does not disappear. Copper output in Chile and Peru — the world's two largest producing countries — faces processing constraints that take months to unwind even after inputs are restored. Freeport-McMoRan has already pushed full restart of its Grasberg mine in Indonesia to early 2028. The supply side is not elastic on a quarterly timeframe.

The verification benchmark for the next session is the LME copper settlement price. If it closes above $14,200 and narrows the gap with Comex, the global shortage reading gains ground over the tariff-front-running reading, and the $14,500 all-time high becomes the next active level. If LME stalls while Comex holds, the spread persists as a US-specific trade — meaningful, but structurally weaker. What would prove the bullish reading wrong is not a lower price, but a narrowing of the sulfuric acid disruption timeline — and that timeline runs through Tehran, not through the Fed.