Aluminium rallied strongly in China as investors positioned themselves for state measures to curb supply.
Shanghai futures rose to their highest level in nearly six years as trading volumes for August appeared on course to reach an all-time high.
The Chinese authorities are closing unlicensed production facilities and planning further moves to curtail output as they look to ease pollution.
Shanghai aluminium surged to over RMB16,600 a tonne in Thursday´s trading session, for a rise of around 3% on the day. The metal was trading at around RMB14,600 a tonne early last month.
Aluminium has performed strongly over the past couple of years, having risen from a trough of RMB9,600 a tonne in November 2015 amid hopes of firming demand.
More recent price action is being driven by expectations of big Chinese production cuts.
Citigroup estimates that moves to end unlicensed production capacity will cut Chinese output by around 4 million metric tonnes a year.
Meanwhile, a further 1 million tonnes is forecast to be trimmed through production curbs mandated by the Chinese government to reduce pollution.
China Hongqiao Group, the world´s single biggest producer, has pledged to shut down around 30% of its overall capacity.
Non-Chinese producers have been calling for some time for China´s output to be curbed, which currently constitutes around 55% of global aluminium supply.
Higher prices could potentially see some producers outside China ramp up output.
JP Morgan, however, expects aluminium prices to rise further during the fourth quarter of this year as the market continues to respond to China´s supply-side reforms.