SHANGHAI, Dec. 20 (SMM) –Shanghai spot copper offers were quoted between premiums of positive RMB 0-120/mt today. Traded prices for standard-quality copper were between RMB 54,200-54,450/mt, and RMB 54,300-54,600/mt for high-quality copper. SHFE copper prices fell from initially increasing, but spot copper premiums failed to hold firm, as cargo-holders took this opportunity to aggressively move goods. The supply of imported copper was very sufficient, but market transactions remained very limited.