US copper futures surged up their 20-cent daily limit early on Tuesday, prompting the New York Mercantile Exchange to halt trade for 15 minutes, floor dealers said.
A wave of speculative money was seen flowing back into the metals markets following Monday's probe of key support levels, they added.
"If you look across all of the metals, they all have the same pattern, rejecting Monday's probes lower and certainly falling into support ranges, with copper probing down to around $3.25 a lb area, which certainly was a consolidation zone in this market," said one COMEX floor dealer.
By 9:46 am EDT (1346 GMT), copper for July delivery surged 20.00 cents or about 5.8 percent to $3.6615 a lb, causing the exchange to halt trading in COMEX copper futures and options for 15 minutes.
Spot May copper climbed 19.00 cents or 5.2 percent to its morning peak at $3.83 but was still below the all-time COMEX record of $4.16 set on May 11. COMEX copper volume at 9:00 am was estimated at only 2,000 lots.