LONDON – The best start to a year for commodities since 2008 is leaving copper in the dust.

The metal is one of the weakest of the 22 raw materials in the Bloomberg Commodity Index of returns this year and the worst of the major metals.

"If you look at where iron ore, coking coal or oil have gone this year, copper really has lagged," Tyler Broda, an analyst at RBC Capital Markets in London, said by phone. "There is no question that right now copper is relatively tenuous in terms of the outlook. We’re definitely picking up a more neutral near-term outlook on copper than previously."

Chinese demand for the metal used in pipes and wires is key to that outlook.

The country is walking a tightrope between reining in speculative property markets and buoying economic growth. A market frenzy that saw prospective buyers throng real-estate agents in Shanghai earlier this year, clogging traffic and forcing police to restore calm, has led some cities to impose curbs.

Liberum Capital Ltd. sees Chinese house prices falling in the second half after a slowdown last month as earlier stimulus measures wear off or are reined in. Sales of construction equipment in China are stumbling, suggesting weakness.

“As house prices roll off, so will investment,” said Ben Davis, an analyst at Liberum. “So demand falls just when more supply is coming online and prices fall.” Real estate and related business are the biggest drivers for copper demand, he said.

That’ll hurt mining stocks, according to Liberum.

Copper miners Antofagasta Plc and Kaz Minerals Plc are the worst performers on the FTSE 350 Mining Index this quarter as the metal’s weak outlook adds to company-specific problems. Glencore Plc, the world’s largest copper supplier and third-largest producer of the mined metal, is the only other share on the index that’s fallen in the period.

Other mine operators have been rising, buoyed by a broad recovery in commodities this year. Zinc has rallied 26% this year, while aluminum is up 8.3% and nickel 4% on the London Metal Exchange. Copper on the other hand is flat.

Part of the problem is that the metal is stacking up in warehouses in China and around the world. Stockpiles in LME depots expanded by a quarter this month, while China built up enough part-processed copper for its needs last year, according to Morgan Stanley. The country, traditionally a net importer, has boosted exports this year.

The market is struggling because the main consumers including infrastructure and real estate are working through last year’s stocks, Morgan Stanley said.

"Copper appears to have missed out on the general rally," Tom Price, an analyst at the bank in London, said by phone. The "price is languishing."