SHANGHAI, Mar. 13 (SMM) –Spot copper offers were quoted between discounts of negative RMB 50/mt and premiums of positive RMB 30/mt in Shanghai in the morning business. Traded prices for standard-quality copper were between RMB 59,800-59,950/mt, and RMB 59,850-60,050/mt for high-quality copper. SHFE copper prices rebounded slightly and rose abruptly near the midday, but cargo-holders in spot markets still quoted prices firm, and cargo-holders of high-quality copper refused to move goods at discounts. The supply of low-quality hydro-copper was limited. The price gap between standard- and high-quality copper was relatively small, so market activity for high-quality copper was active. Downstream producers continued to stand on the sidelines above RMB 60,000/mt, but bought aggressively at the lows in the morning session.