SHANGHAI, Nov. 20 (SMM) – Spot copper in Shanghai was quoted at a premium of RMB 90-190/mt over SHFE 1312 copper contract on Wednesday. Traded prices were RMB 50,680-50,740/mt for standard-quality copper, and RMB 50,740-50,820/mt for high-quality copper. The price spread between standard-quality copper and high-quality copper was limited, but trading was thin. Some traders bought spot copper while selling SHFE copper. Downstream producers stayed out of the market following bargain hunting a day earlier.