Investments in commodities are expanding at the quickest pace in six years on signs of rising economic growth, even as JPMorgan Chase & Co. and Goldman Sachs Group Inc. warn that some prices have rallied too fast.

The number of futures contracts on 24 commodities from oil to copper rose 9.3 percent last month, the most since January 2006, according to data compiled by Bloomberg. Speculators are the most bullish since November, Commodity Futures Trading Commission data show. Gold and silver had the best start to a year since 1983, orange juice posted its biggest rally in more than three decades, the LMEX gauge of six industrial metals rose the most since 2006, and cattle futures advanced to a record.

The Standard & Poor’s GSCI gauge of 24 commodities rose 0.4 percent to 664.43 at 5:01 p.m. Singapore time. The UBS Bloomberg CMCI index of 26 raw materials climbed 0.5 percent to 1,606.053.

CRUDE OIL

Oil rose for a second day in New York on speculation that Federal Reserve plans to keep U.S. interest rates near a record- low will bolster economic growth and stoke fuel demand in the world’s biggest crude consumer.

Crude for March delivery rose as much as 84 cents to $100.24 a barrel on the New York Mercantile Exchange and was at $99.82 at 3:56 p.m. Singapore time. The contract closed 45 cents higher at $99.40 yesterday. Prices are up 14 percent in the past year.

Brent oil for March settlement was up 74 cents, or 0.7 percent, at $110.55 a barrel on the London-based ICE Futures Europe exchange. The European contract’s premium to March Nymex crude was $10.73 a barrel. That’s down from a record $27.88 on Oct. 14.

Speculators decreased wagers on rising commodity prices to the lowest since July 2009 amid concern that Europe’s inability to contain its debt crisis will crimp demand for raw materials as global growth slows.

Money managers cut combined net-long positions across 18 U.S. futures and options by 25 percent to 562,508 contracts in the week ended Nov. 22, Commodity Futures Trading Commission data show. That’s the biggest decline in eight weeks and the lowest since July 14, 2009. Corn wagers tumbled 25 percent, the most since June 2010, and bets on lower copper prices doubled.

Employment grew by 103,000 workers in the month, the Labor Department said.