The SRB will auction 20,000 tonnes of copper on November 16, which should in theory depress spot prices. But instead they have risen, in part because many traders believe the bureau's release will do little to change the balance of supply and demand.
Spot prices rose to 38,300-38,480 yuan ($4,737-$4,760) on Thursday, up 115 yuan from Wednesday.
November and December futures also gained, widening the backwardation.
A wider backwardation is normally the sign of tighter supply. Forward selling pressured other contracts, traders said.
The most active contract, January, ended at 36,580 yuan, down 90 yuan from Wednesday's close. Combined trading volume rose to 84,742 lots, from 53,430 lots on Wednesday.
Benchmark LME copper futures were at $3,956 a tonne, up from $3,947.50 a tonne at the same time on Wednesday. Shanghai aluminium futures were flat too slightly higher on Thursday.
The December contract was most active, although it closed unchanged at 17,180 yuan a tonne, while January was also unchanged at 17,220 yuan. Trading volume fell to 6,400 tonnes, from 10,714 tonnes.
Benchmark LME aluminium futures were at $2,017 a tonne, up $4.50 a tonne from Wednesday's close.