SHANGHAI, Sept. 20 (SMM) –Shanghai spot copper offers were quoted between premiums of positive RMB 0-100/mt today. Traded prices for standard-quality copper were between RMB 63,050-63,200/mt, and RMB 63,100-63,350/mt for high-quality copper. As SHFE copper prices continued to fall, spot copper prices were again down more than RMB 1,000/mt. Cargo-holders tried to hold premiums, but market supply remained ample. With bearish sentiment dominating the market, downstream producers and traders kept cautious towards purchases, dampening trading sentiment.