SHANGHAI, Jan. 30 (SMM) –Copper futures prices rebounded marginally over the past week, but the price difference between bare bright (including tax) and refined copper held between RMB 800-1,000/mt. Owing to tight market supply, scrap copper prices remained firm and enjoyed less price advantage versus refined copper. Copper rod producers thus bought scrap copper merely on an as-needed basis. Cargo-holders of #2 scrap copper and other scrap copper goods with low Cu content also insisted on firm prices, which prompted smelters to reduce scrap copper purchase volumes. SMM believes the scrap copper supply constraints are unlikely to ease over the near term.