Speculators increased their bullish commodity wagers for the first time since November as signs of accelerating growth in China and the U.S. drove prices higher for a fourth consecutive week.

Hedge funds and other money managers raised their net-long positions across 18 U.S. futures and options by 2.4 percent to 691,832 contracts in the week ended Dec. 31, the first gain since Nov. 27, U.S. Commodity Futures Trading Commission data show.

Cotton holdings climbed to the highest since September 2011, and those for sugar reached a nine-week high. Gold wagers rose for the first time in three weeks.

The Standard & Poor’s GSCI gauge of 24 raw materials rebounded 3.8 percent since reaching a three-month low on Nov. 5. China’s manufacturing unexpectedly expanded at the fastest pace in 19 months in December, a private survey showed Dec. 31. The U.S. added more jobs than forecast last month, capping a third year of rising payrolls, the government said Jan. 4.

“In 2012, we had a lot of liquidating by hedge funds, but there’s an incentive to reverse that because of growth in emerging markets and especially China,” said Rob Haworth, a senior investment strategist at U.S. Bank Wealth Management in Seattle, which oversees about $111 billion of assets. “It’s going to be a good year for commodities.”

Commodities Rally
The final reading of a Chinese Purchasing Managers’ Index was 51.5 in December, figures from HSBC Holdings Plc and Markit Economics showed. That compares with 50.5 in November, and the median forecast of 14 economists surveyed by Bloomberg was for a reading of 50.9. A level above 50 indicates expansion. China will accelerate for at least the next six months, the median of estimates from 33 economists compiled by Bloomberg show.

U.S. payrolls rose by 155,000 workers last month, topping analysts’ projection of 152,000, the Labor Department said. For all of 2012, the economy created 1.84 million jobs, matching the gain in 2011 in the best back-to-back growth since 2005-2006. Service industries, which make up almost 90 percent of the economy, expanded at the fastest pace in 10 months, an index from the Institute for Supply Management showed Jan. 4.

The “acute phase” of the global economic slowdown may be ending, boosting prospects for commodities, Credit Suisse Group AG analysts led by New York-based Ric Deverell wrote in a report Jan. 3.

Spending Cuts
An end to central-bank stimulus would probably mean lower commodity prices, said Stanley Crouch, who helps oversee $2 billion of assets as chief investment officer at New York-based Aegis Capital Corp.

Several Federal Reserve officials said it would “probably be appropriate to slow or stop” the central bank’s $85 billion monthly bond-buying program sometime this year, according to minutes of December policy meeting released Jan. 3.