Spot copper in Shanghai was quoted at a contango of RMB 0-100/mt and a backwardation of RMB 0-10/mt over SHFE 1311 copper contract on Friday. Traded prices were RMB 51,780-51,840/mt for standard-quality copper, and RMB 51,820-51,920/mt for high-quality copper. Contango narrowed, especially for standard-quality copper. Backwardation was reported only for Guixi copper. Traders and downstream producers purchased modest amounts of goods at the bottom. In the afternoon, falling SHFE copper prompted arbitragers to sell aggressively, with spot copper offered between a contago of RMB 100 and a backwardation of RMB 20/mt. Some traders bought in spot markets and sold futures, and a few downstream buyers also purchased at lows, with spot trading improving. Traded prices were between RMB 51,500-51,700/mt. SHFE copper stocks edged up 37 lots to 172,146 lots last week.