The most-traded September copper contract on the Shanghai Futures Exchange SCFcv1 fell 1.1% to 70,680 yuan ($9,867) a tonne.

Three-month copper on the London Metal Exchange (LME) CMCU3 traded 0.2% higher at $8,789.50 a tonne. It had earlier fallen to $8,716 a tonne, near a 21-week low of $8,714 hit on Aug. 5.

“The global economic growth cycle has turned lower, which means all markets can synchronize and move together. With physical inventories rising and processing and refining costs (TC/RC) recovering, copper bulls have no more stories to tell,” said Sandeep Daga, director of the Metals Intelligence Center.

Rising TC/RC, or the fee that copper smelters charge miners to process the raw material, implies that the supply of copper concentrate in the spot market, which has been tight, is improving - one reason investors are bullish on copper prices.

LME copper inventories have nearly tripled in less than three months to 294,750 tonnes as of Wednesday, with recent shipments arriving at LME warehouses in South Korea and Taiwan near China.

Physical demand improves as prices fall, but risk-off sentiment in financial markets will affect prices more than physical goods, Daga said.

LME aluminium CMAL3 fell 0.9% to $2,273.3 a tonne, nickel CMNI3 fell 0.9% to $16,155, lead CMPB3 fell 0.4% to $1,959.5, tin CMSN3 rose 0.7% to $30,195 and zinc CMZN3 rose 1.8% to $2,627.5.

SHFE aluminium SAFcv1 was almost flat at 18,945 yuan/t, nickel SNIcv1 fell 1.7% to 127,180 yuan, zinc SZNcv1 fell 0.8% to 21,835 yuan while lead SPBcv1 rose 0.1% to 17,345 yuan and tin SSNcv1 rose 0.3% to 245,360 yuan.