Copper traders are the most bullish in 15 months on mounting confidence that the U.S. economy will rebound at a time when China's recovery is gaining momentum.

Copper climbed to a three-month high Friday after data showed faster economic growth and higher profits for industrial companies in China, the biggest user of the metal.

Global equities rallied to an almost 21-month high last week after China's expansion accelerated for the first time in two years and an index of U.S. leading indicators rose the most in three months.

"The U.S. will show at least moderate growth going forward this year, and U.S. stimulus should lead to higher commodity prices," said Daniel Briesemann, a commodities analyst at Commerzbank AG in Frankfurt. "China's economy is definitely gaining momentum and ... will be the main driver."

Northeastern Minnesota has one of the world's largest deposits of untapped copper, nickel, platinum, palladium, cobalt and gold.

The potential for copper clearly has gotten the attention of traders. The metal jumped as much as 11 percent from a two-month low set Nov. 9, reaching $8,318 as of Friday. Since December 2008, when the Federal Reserve expanded asset purchases, copper has more than doubled in price.

North America consumes roughly 11 percent of the world's copper and China 42 percent.

But there are signs that copper consumption is slowing. China's refined-copper imports slid 41 percent last year, according to customs data. Copper inventories in warehouses monitored by the LME, the largest metals bourse, are at the highest in 13 months after jumping 78 percent from an almost four-year low set Oct. 16, exchange data show. The stock buildup points to "weak physical demand," said Robin Bhar, an analyst at Societe Generale SA in London.