Copper prices tumbled nearly 7 percent on Thursday, the biggest one-day collapse in four weeks, on fears of a double-dip recession and growing doubts that Europe will get a handle on its debt crisis. In New York, the key December COMEX contract dropped 20.05 cents or 6.2 percent to settle at $3.0575, close to the bottom end of its $3.2350 to $3.0310 session range.
Volumes perked up Thursday as the selling intensified. Close to 64,000 lots traded in New York, nearly 12 percent above the 30-day average, according to Thomson Reuters preliminary data. Copper extended a reversal from Monday's three-week high near $3.50 in New York and $7,660 in London, leaving both markets vulnerable for a retest of their 2011 lows, at $2.99 and $6,635, respectively.