Copper rallied as much as 5 percent to a fresh one-month high Wednesday, as investors began to price in the possibility of looser monetary policy in China and stepped up purchases as supply shocks escalated at the world's No 2 mine. In New York, the key December COMEX contract climbed 6.95 cents to settle at $3.49 per lb, after moving between $3.3960 and its own one-month high at $3.5880.
Volumes picked up a bit alongside the recent price volatility. close to 69,000 lots traded late in New York, more than 10 percent above the 30-day norm, according to Thomson Reuters preliminary data.