Comex copper futures ended at 11-day highs on Friday, boosted by a softer dollar in the face of weaker-than-expected US GDP data, while already low metal inventories fell further to give the market an added boost, dealers said.
Active September copper settled up 1.45 cents at $1.3080 a lb. on the New York Mercantile Exchanges Comex division after trading from $1.28 to $1.3130, its highest mark since July 19. Spot August advanced 1.65 cents to $1.3080 and the rest rose 0.40 to 1.60 cents.
"Copper went through $1.30 on the draw in Shanghai warehouse stocks, firmer Chinese base metals prices, while the GDP number was weaker than expected and the dollar is under a little pressure," said James Quinn, AG Edwards & Sons commodity commentator.
He said next resistance lurked at $1.31, basis the September contract, which, if surpassed, could trigger further fund buying. Quinn pegs technical supports down around $1.2650-1.27 a lb. Trade selling at copper highs and profit taking in the euro capped gains, traders said.
The market stretched higher at first as the euro rose against the dollar to about $1.21 in the wake of a 3-percent rise in US gross domestic product in the second quarter.
A lower US currency usually lifts demand for dollar-denominated metals like copper as they become more affordable for traders using foreign money.
US GDP was seen as modest in the April-June period after an upwardly revised 4.5 percent clip at the start of the year.
Economists had looked for a 3.6 percent rise. Meanwhile, business activity in the Midwest picked up in July as the Chicago Purchasing Management indexes for last month rose to 64.7 from June's 56.4 level.
The data were seen as positive overall, leading the dollar to shave losses in the afternoon. Nonetheless, buying in copper was sustained before the weekend and the end of the month, despite the dollar strength, on supply-side concerns and falling inventories, traders said.
Canadian miner Noranda declared partial force major overnight on output from its Chilean Altonorte copper smelter after a fire damaged the facility in the week.
It said it expected to lose less than 30,000 tonnes of concentrate while repairs took place.