By Amrith Ramkumar 

Copper prices rose last week to their highest level in seven months, highlighting how a brighter view of the world economy is supporting riskier corners of the market.

Because it is an industrial metal critical to the manufacturing and construction industries, copper is extremely sensitive to investors' perception of global growth. The metal is closely tied to China, which accounts for roughly half of the world's consumption.

Worries that the U.S.-China trade war would limit demand had hurt prices earlier in the year, leaving them trading for months in a narrow band, but optimism about an agreement between the world's two largest economies has helped them rise about 6% in the past eight sessions. Prices on Thursday closed at their highest level since early May.

Copper's rise underscores how better-than-feared economic data are supporting a range of markets near the end of the year. Stocks around the world and other commodities have also posted gains since the U.S. and China reached a tariff truce in mid-October, and some analysts say an eventual deal could give the world economy a powerful boost next year.

U.S. and Chinese officials on Friday announced a limited "phase one" agreement to halt the trade war between the countries.

The recent rally is a boon for producers and bullish investors who had watched copper prices languish for months despite falling inventories and lower-than-needed investment in new mines around the globe.

"We remain very positive about the outlook," said Richard Adkerson, chief executive of copper producer Freeport-McMoRan Inc., on the company's third-quarter earnings call in late October. "The demand for copper remains relatively strong throughout the world."

Freeport shares have risen 20% in the past three months, paring some of their monthslong decline. Shares of Southern Copper Corp. have also advanced lately and are up 35% for the year, outpacing the S&P 500's 26% climb.

Analysts say the long-term outlook for copper looks positive. Supply remains relatively constrained because of disruptions in countries such as Indonesia and Chile, while many expect demand to increase as more consumers transition to using electric vehicles. Because investors remained wary of a short-term demand slowdown, however, anticipation of those future shortages had done little to lift copper prices for much of the year.

In late October, the International Copper Study Group, a body of copper producers and consumers, lowered its target for 2019 demand growth to 0.3% from about 2% in May. The downward revision showed how much trade concerns have weighed on sentiment this year.

But optimism about trade progress and improving manufacturing data are starting to change that. Copper's recent advance has come with officials in the U.S. and China laying the groundwork to delay U.S. duties that were scheduled to take effect Sunday on Chinese consumer goods as diverse as laptops and clothing.

As part of the initial trade pact, the U.S. canceled plans to impose those duties and Beijing agreed to purchases of American farm goods and other products.

"Optimism on trade in the aftermath of the agreement will probably continue to support commodity prices next week," Capital Economics analysts said in a note to clients.

If the tariffs eventually take effect, though, some analysts caution that worries about global growth could drag down stocks and commodities again, as they did in May and August. The levies would threaten the steady consumer spending that has powered the U.S. economy so far this year.

Hedge funds and other speculative investors remain relatively cautious the industrial metal can extend its rebound, Commodity Futures Trading Commission data show, meaning that a broader trade agreement and more upbeat economic data could add fuel to the rally. Bearish copper bets by speculators have exceeded bullish wagers for six months, though net bets on declining prices fell to their lowest level since late April during the week ended Dec. 10.

Even with their recent rebound, copper prices are still 6.3% below their peaks hit in mid-April. Other industrial metals such as aluminum and tin have also struggled for momentum, reflecting worries that material demand in China could continue to slow down.

Although the private Caixin manufacturing purchasing managers index rose for the fourth consecutive month in November, Chinese policy makers have been struggling with rising consumer inflation and deepening industrial-price deflation. The slowdown is increasing focus on future trade developments, and some copper-market watchers expect the uncertainty to keep prices swinging within their current monthslong trading range.

"We think that's still going to be the theme for the next few months," said Daniel Ghali, a commodity strategist at TD Securities. "We don't think the turnaround in growth is going to happen as fast as people think."

Write to Amrith Ramkumar at amrith.ramkumar@wsj.com

(END) Dow Jones Newswires

December 15, 2019 11:09 ET (16:09 GMT)

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