SHANGHAI, Mar. 21 (SMM) – Copper was offered at a premium of RMB 20-120/mt over SHFE current-month contract prices on Friday. Traded prices were RMB 45,280-45,420/mt for standard-quality copper and RMB 45,340-45,480/mt for high-quality copper. As SHFE copper prices lacked impetus to rebound, cargo holders moved goods steadily in the morning trade, with spot premium almost unchanged from Thursday. Spot premium later inched up in the wake of a sharp fall in SHFE copper prices. Downstream produces stepped up purchasing goods ahead of the weekend. Trading activity improved appreciably for standard-quality copper, but was restrained a tad for high-quality copper at a premium of around RMB 100/mt. A majority of speculators preferred spot copper on Friday due to high volatility in SHFE copper prices, with modest trading volumes.