Copper posted the biggest gain in almost three months as strong economic data from China fueled speculation that demand will strengthen in the Asian nation, the world’s largest metals consumer. An index of global mining stocks advanced for the first time in six days.

China’s broadest measure of new credit exceeded estimates in August, rebounding from a month earlier and bolstering evidence that growth is stabilizing. Chinese reports this week on factory output, investment and retail sales all exceeded economist estimates.

“The Chinese data is improved,” Michael Turek, the head of base metals at BGC Partners Inc. in New York, said in an e-mail.

“Credit has been easier. That enables manufacturing to operate more smoothly and profitably and reduces bankruptcies.”

Copper for delivery in three months rose 2.6 percent to $4,771.50 a metric ton ($2.16 a pound) at 5:50 p.m. on the London Metal Exchange, the biggest increase since June 15.

The Bloomberg World Mining index of producers added 0.4 percent, heading for its first gain since Sept. 6.

Users, including power-wiring companies, are stepping up purchases of copper ahead of China’s autumn festival after prices fell, Xu Maili, an analyst with Everbright Futures Ltd., said by phone from Shanghai. The three-day Chinese holiday starts Thursday.

Eoin Treacy's view

The Chinese market is closed tomorrow and Friday for the Mid-Autumn Festival and the annual golden week holiday will be between October 2nd and 7th inclusive. Therefore there is some merit to the argument that stockpiling ahead of the holidays may have contributed to recent firming in copper prices. 

However when we look at the medium-term chart there is clear evidence of a loss of momentum from early this year; following what was a consistent five-year decline. The $2 area has offered support on a number of occasions since January and the ranging consolidation has allowed the moving average to draw increasingly close to where the market is trading. A sustained move above it would signal a return to demand dominance beyond steadying. 

The London Metal Exchange Index is now trading in the region of the trend mean and will need to find support soon if medium-term scope for continued higher to lateral ranging is to be given the benefit of the doubt.