At first glance, the copper inventory picture looks comfortably supplied. Global visible stocks have ballooned by 540,000 tonnes since January 2026 to approximately 1.5 million tonnes, according to JPMorgan data. (FACT: JPMorgan, May 2026) But this aggregate figure conceals a deepening regional dislocation that is distorting price signals and creating opportunities for sophisticated arbitrage while exposing less agile buyers to basis risk.
The driver of the build is overwhelmingly the United States. COMEX copper inventories have surged as market participants rushed to deliver metal into US warehouses ahead of possible 10-15% tariffs on refined copper imports under the 2026 Section 232 review. (FACT: CNBC, May 2026) This is not organic demand building — it is precautionary hedging. In 2025, the CME-LME spread reached a record $1.30/lb, incentivizing massive metal movement into COMEX delivery points. That trade has continued into 2026, creating a wall of metal in US storage while LME-registered warehouses in Europe and Asia hold only moderate tonnage. LME stocks stand at roughly 392–396 kt, a level that provides limited comfort given the pace of concurrent supply disruptions globally. (FACT: Westmetall, May 2026)
China, the world's largest copper consumer, has been actively drawing on its own inventories. Chinese buyers — representing roughly 60% of global demand — have been opportunistic dip-buyers, and China's March 2026 refined copper output hit a record 1.33 million tonnes, suggesting that domestic smelters are operating at full tilt to meet local demand. (FACT: CNBC, TradingEconomics, May 2026) The combination of China's drawdown, moderate LME stocks, and a COMEX stockpile that may prove illiquid for non-US buyers creates a market where "ample" global inventories coexist with genuine availability constraints in Europe and Asia.
The 1.5 Mt global inventory headline is a trap for the unwary. Most of the increase is concentrated in COMEX warehouses and reflects tariff hedging, not surplus. For buyers sourcing copper outside the United States, the effective available inventory is far lower — LME stocks at ~394 kt are only a few weeks of global consumption. The regional dislocation also presents a basis risk: CME-priced contracts may decouple further from LME if tariffs are imposed, creating winners and losers depending on procurement geography. Non-US buyers should treat global inventory data with skepticism and focus on regional availability. US buyers should lock in CME-based supply before any tariff decision removes the arbitrage that has kept US premiums contained. The inventory surge is a mirage — the real copper market is tighter than the aggregate data suggest.