Traders betting commodities will be scarcer and more expensive

American traders are taking their strongest positions on agriculture commodities since September 2012, when the sector in the US was rocked by drought.

New data published by the Commodity Futures Trading Commission show that coffee wagers have reached a 33-month high. Meanwhile, hedge funds raised bullish gold wagers to the highest in more than 14 months amid mounting concern that the US economic recovery is weakening.

A measure of speculative positions across 11 agricultural products jumped 22% to 701,961 contracts, the most since September 2012, the commission data show. The S&P GSCI Agriculture Index of eight commodities climbed 9.7% in February, the biggest monthly advance July 2012. The measure is rebounding after tumbling 22% in 2013, the most since 1981.