SHANGHAI, Mar. 27 (SMM) – Spot copper premiums were RMB 20-100/mt in Shanghai on Wednesday. Traded prices for standard-quality copper were between RMB 55,750-55,800/mt, and RMB 55,780-55,880/mt for high-quality copper. Prices for the most active SHFE copper contracts drifted lower after a high opening, stimulating cargo holders to sell at highs, pushing spot premiums up. Many varieties of high-quality copper was available in the market, whereas standard-quality copper and low-end wet-processed copper were in tight supply, narrowing price spread between these two categories. Downstream producers and middlemen stayed out of the market out of growing bearishness over future prices, keeping transactions muted.