“Illegal” capacity has been closed and smelters in the region around Beijing are, to varying extents, curtailing output to comply with the winter environmental restrictions.

It is also forecasting a bigger deficit of 2.0-2.2 million tonnes in the rest of the world, where visible stocks have been falling for many months.

Inventory registered with the London Metal Exchange (LME) is close to multi-year lows at just 840,000 tonnes, discounting metal awaiting physical load-out.

Unsurprisingly, given such dynamics, the aluminium price in London has been outperforming that in Shanghai.

Equally unsurprisingly, more Chinese aluminium, in the form of semi-manufactured products, has been starting to move through the arbitrage window. December’s tally of 390,000 tonnes was the highest since June 2017.

This is how the global aluminium market has historically rebalanced itself, Chinese surplus leaking out as “semis”.