Copper ended firm on Monday, posting its largest gain in one week, after stronger-than-expected manufacturing data in the United States and China bolstered demand prospects in the world's two largest end-user markets. Copper for December delivery on the COMEX metals division of the New York Mercantile Exchange climbed 5.15 cents, or 1.4 percent, to close at $3.7850 per lb.
The session range ran from $3.7475 to $3.8160. Last week, the benchmark December contract touched a 27-month top at $3.90. Open interest in COMEX copper futures dropped 3,244 lots to 161,220 contracts as of October 29, down from a record peak of 167,063 contracts on October 26.