SHANGHAI, May 8 (SMM) – Quotations for spot copper premiums were between positive RMB 40-80/mt in Shanghai in the morning business. Traded prices for standard-quality copper were between RMB 57,980-58,030/mt, and RMB 58,020-58,080/mt for high-quality copper. As SHFE copper prices rebounded marginally, increases in spot copper premiums were restricted. Some cargo-holders quoted firm prices as copper prices exhibited resilience. Spot copper supply remained stable, but market activity failed to improve.