Copper ended down for a second straight day on Thursday as a strengthening dollar and heightened concerns about slowing global economic growth triggered a wave of risk aversion across the commodities complex. In New York, the key September COMEX contract dropped 5.05 cents to settle at $4.0565 per lb.
Volumes picked up as the losses mounted. More than 62,000 lots traded late in New York, a third above the 30-day norm, according to preliminary Thomson Reuters data. "We have selling in large volumes and we're still not able to put pressure through the $4 support level," said Ralph Preston, futures analyst with HeritageWestFutures.com in San Diego, California.