SHANGHAI, May 3 (SMM) – Spot copper was quoted between discounts of negative RMB 20/mt and premiums of positive RMB 40/mt in Shanghai in the morning business. Traded prices for standard-quality copper were between RMB 58,280-58,340/mt, and RMB 58,320-58,400/mt for high-quality copper. SHFE copper prices trended lower after starting lower. Spot copper supply was tight, stimulated by news that Jiangxi Copper and other smelters and trading firms delivered copper to the LME warehouses. As a consequence, domestic copper held price quotes firm, and premiums for high-quality copper climbed. Standard-quality copper prices were also firm owing to tight supply. Speculators bought aggressively, while downstream producers purchased on an as-needed basis.