SHANGHAI, Apr. 24 (SMM) – Spot copper in Shanghai was quoted at a premium of RMB 150-250/mt over SHFE 1305 copper contract on Wednesday. Traded prices for standard-quality copper were between RMB 50,250-50,430/mt, and RMB 50,300-50,550/mt for high-quality copper. SHFE 1308 copper contract staged a big rally, leaving little room for arbitrage. Spot copper suppliers held back goods while holding offers firm. The most active SHFE copper contract rose nearly RMB 400/mt towards mid-day, and spot copper premium remained firm. Middlemen continued to watch from the sidelines, while downstream producers purchased to need.