SHANGHAI, Dec. 9 (SMM) –Shanghai spot copper offers were quoted between discounts of negative RMB 150/mt and premiums of positive RMB 20/mt today. Traded prices for standard-quality copper were between RMB 57,700-57,800/mt, and RMB 57,800-57,900/mt for high-quality copper. SHFE copper prices failed to move higher after a low open, but sufficient copper supply caused copper to generally be traded at discounts, while only some cargo-holders could maintain slight premiums. Market transactions improved slightly due to approach of the weekends.