Base metals close mixed on Shanghai night session; nickel up 0.75%, alumina up 1%

The split between international copper's marginal gain and SHFE copper's fractional decline points to a market driven by local positioning rather than a shared macro signal, which makes the broader strength in aluminium, zinc, nickel and alumina more notable than any single move. Alumina's 1% rise stands out against the modest gains elsewhere, and whether that outperformance reflects feedstock-specific factors or simply thin night-session liquidity is the open question. For anyone tracking Chinese metals demand, the divergence between the two copper contracts is the detail worth watching.