SHANGHAI, May 24 (SMM) – Spot copper in Shanghai was quoted at a premium of RMB 300-550/mt over SHFE 1306 copper contract on Friday. Traded prices for standard-quality copper were between RMB 53,600-53,750/mt, and RMB 53,800-54,000/mt for high-quality copper. SHFE 1309 copper contract prices rebounded, allowing spot copper suppliers to hold prices firm. Premium of high-quality copper rose on tight supply and high buying interest, while prices of standard-quality copper were more than RMB 200/mt lower than those of high-quality copper due to ample supply. Downstream producers purchased on an as-needed basis, while middlemen contributed most to trading.