“The risk appetite has certainly improved over the last several months,” said Nelson Louie, the global head of commodities at New York-based Credit Suisse Asset Management, who helps manage $11.3 billion. “The overall U.S. economy has shown resilience, and China seems to be improving as well.”

Investors withdrew a net $929 million from commodity funds in the week ended March 20, said Cameron Brandt, the director of research for Cambridge, Massachusetts-based researcher EPFR Global, which tracks money flows. Gold and precious metals had an outflow of $978 million.

Gold Gains

Gold prices have risen 1.8 percent in March, heading for the first monthly gain since September. The metal is still down 4.1 percent this year as the U.S. unemployment rate fell and assets in exchange-traded products backed by gold dropped 6.7 percent. Investors increased their bullish bets by 63 percent to 70,193 contracts, the biggest expansion since September 2008.

The precious metal has jumped 81 percent since the end of 2008 as central bank measures intended to stimulate economic growth increased speculation that inflation will accelerate. The Federal Reserve on March 20 left unchanged plans to hold its target interest rate near zero percent as long as U.S. unemployment remains above 6.5 percent. The jobless rate last month was 7.7 percent.

Money managers increased their bullish bets on natural gas to 46,148 contracts, from 2,995 a week earlier, the CFTC data show. Oil wagers climbed 3.2 percent to 172,268 contracts, and those for gasoline rose 1.4 percent to 77,801 contracts. Natural gas advanced 18 percent this year as production gains slowed and cold weather bolstered heating demand.

Farm Bets

A measure of speculative positions across 11 agricultural products from wheat to coffee to cattle increased 9.1 percent to 265,475 contracts, the highest since Feb. 12.

Wagers on higher corn prices increased 66 percent to 145,535 contracts, the biggest gain since July 2010. Speculators reduced their negative outlook for wheat to 33,457 contracts from a net-short position of 41,519 a week earlier.

Corn stockpiles before the next harvest will fall to 632 million bushels, the lowest since 1996, the U.S. Department of Agriculture said March 8. The agency raised its forecast for use of the grain in animal feed by 2.2 percent to 4.55 million bushels. Soybean inventories may drop to the lowest since 2004.