Updated
Updated · CNBC · Aug 14
COMEX-LME Copper Spread Signals 14.6% Odds of New U.S. Tariffs
Updated
Updated · CNBC · Aug 14

COMEX-LME Copper Spread Signals 14.6% Odds of New U.S. Tariffs

1 articles · Updated · CNBC · Aug 14

Summary

  • 14.6% is the tariff probability implied by the current COMEX premium over delivered LME copper for a proposed 15% U.S. refined-copper duty by January 2027, according to Societe Generale.
  • 37% is the implied probability of a 30% duty by January 2028, reflecting how traders now use the COMEX-LME spread as a live gauge of Section 232 tariff risk rather than a traditional arbitrage signal.
  • 200,000 metric tons of copper entered the U.S. in July—the highest in 12 years—as a wider COMEX premium keeps pulling metal into the country ahead of a delayed Commerce Department decision.
  • 50% tariffs already apply to semi-finished copper products, while Commerce has recommended phased universal tariffs on refined copper as Washington worries about import dependence amid AI, grid and defense demand.
  • Near $6.90 a pound last week, copper is also being supported by tight mine supply and intensifying U.S.-China competition for metal, leaving the market constructive but volatile.

Insights

What happens to copper prices and U.S. inventories if the expected tariffs are delayed, softened, or never imposed?
If refined copper tariffs arrive in 2027 and 2028, who gains from today’s stockpiling—and who gets stuck with higher costs later?
Is copper’s U.S.-London price gap really a tariff signal, or a warning that AI demand and mine shortages are colliding?