Hedge funds are the most bullish on diesel in almost five months as the coldest January in 20 years boosted demand and cut U.S. supply to the lowest in a decade. Money managers increased net-long positions, or wagers on rising prices, by 29 percent in the week ended Feb. 4, the third consecutive gain, U.S. Commodity Futures Trading Commission data show. Long positions expanded by 5,016 contracts and short wagers fell by 1,020. Prices for diesel, traded as a proxy for heating oil, rose to the highest since 2012 as frigid weather spread across the U.S. Northeast, leading to curbs on natural gas pipelines that boosted oil demand. Refineries beginning seasonal maintenance may cut production this month, further reducing stockpiles near New York Harbor that are already the lowest since May 2003. “This is in reaction to cold weather supporting distillate demand and inventories continuing to decline as refineries […]