SHANGHAI, Jun. 27 (SMM) –Spot copper premiums surged to RMB 300-380/mt last week from the previous week's RMB 20-100/mt following the delivery of SHFE 1206 copper contracts. Some scrap copper cargo-holders became more willing to move goods after copper prices rose, which caused the price differential between bare bright and refined copper to inch slightly higher to RMB 700-950/mt. This price differential enticed some low-oxygen copper rod producers to switch back to bare bright copper as the price advantage of scrap against refined copper widened slightly. As the supply of domestic scrap copper has yet to improve, SMM sees little room for scrap copper to improve further in the near term.