SHANGHAI, Nov. 21 (SMM) – Spot copper in Shanghai was quoted at a premium of RMB 80-180/mt over SHFE 1312 copper contract on Thursday. Traded prices were RMB 50,420-50,480/mt for standard-quality copper, and RMB 50,480-50,580/mt for high-quality copper. Holders of imported copper became more willing to sell to raise cash. Trading activity was brisk early in the morning, but diminished once copper prices rose. Suppliers of Guixi copper insisted on high offers. Traders bought in small amounts, while downstream producers watched from the sidelines.