Aluminum markets showed a stark divergence across exchanges this week. COMEX aluminum futures posted their worst weekly decline of 2026, falling 5.8% to $3,574.50/mt, while LME three-month prices rebounded 1.1% to $3,536/mt from a test of $3,500/mt support.
The COMEX sell-off reflects positioning by speculative shorts ahead of the June contract expiry, compounded by profit-taking after aluminum's rally to $3,855/mt earlier in the month. The retreat has erased gains from the first week of June.
LME cash aluminum traded at $3,608-3,669/mt on June 9, with the cash-to-3-month contracdo narrowing, signaling that nearby supply is not as abundant as the broader futures curve suggests. Stocks declined 0.64% to 319,925 tonnes.
On the Shanghai Futures Exchange, aluminum lost 1.42%, settling at 24,610 CNY/mt. The discount to international prices has widened, creating an arbitrage opportunity for Chinese exports if domestic demand softens further.
The divergence between COMEX and LME pricing is partly structural: COMEX inventory data shows rising warehousing levels in US locations, while LME European and Asian warehouses continue to see drawdowns, reflecting regionally divergent supply-demand dynamics.
The COMEX-LME divergence creates an arbitrage window for buyers with cross-exchange access. For most procurement teams, the LME recovery from $3,500/mt support signals that the dip is a buying opportunity. Layer in Q4 2026 coverage near $3,500-3,550/mt.