SHANGHAI, Oct. 20 (SMM) –Shanghai spot copper offers were quoted between premiums of positive RMB 500-650/mt today. Traded prices for standard-quality copper were between RMB 52,300-52,500/mt, and RMB 52,400-52,600/mt for high-quality copper. As SHFE copper prices fell by their daily limit of 6% and the SHFE/LME copper price ratio was down to 7.3, spot copper premiums rose significantly. Domestic copper cargo-holders increased sale volumes. Downstream producers with sufficient orders increased purchases at low prices, while speculators’ buying interest was dampened due to higher copper premiums. On account of bearish sentiment, market transactions became cautious.