SHANGHAI, Sept. 2 (SMM) –Shanghai spot copper offers were quoted between discounts of negative RMB 30/mt and premiums of positive RMB 30/mt today. Trade prices for standard-quality copper were between RMB 67,950-68,030/mt in the morning business, and RMB 68,000-68,150/mt for high-quality copper. Due to optimistic market expectations of the following week, cargo-holders were unwilling to make transactions at discounts, reducing market supply. SHFE copper prices moved lower after a low open, and spot high-quality copper held offers at premiums. Downstream producers took advantage of a drop in SHFE copper prices to make more purchases.