SHANGHAI, Dec. 12 (SMM) –Shanghai spot copper offers were quoted between discounts of negative RMB 200-80/mt today. Traded prices for standard-quality copper were between RMB 57,350-57,450/mt, and RMB 57,400-57,600/mt for high-quality copper. SHFE copper prices began to slide immediately after the opening, but copper discounts were reported across the board and expanded all the way due to sufficient copper supply, a signal that cargo-holders were eager to sell to generate cash. Downstream producers still made purchases on an as-needed basis, and speculators only had buying interest in high-quality copper with large discounts, highlighting cautious trading on Monday