Natural-gas prices hit $5 a million British thermal units for the first time in 3 ½ years on expectations that continued cold weather would keep demand high for the heating fuel. Natural gas for February delivery rose as high as $5.026/mmBtu on the New York Mercantile Exchange before pulling back slightly. The February contract recently traded up 26.4 cents, or 5.6%, at $4.994/mmBtu. The rally highlights concerns about supply, after several years of booming U.S. production. The amount of gas stored in the U.S. has dwindled in recent weeks as heating demand has ramped up. Inventories as of Jan. 17 stood at 2.423 trillion cubic feet, 13% below the five-year average for the week. Natural-gas prices have climbed more than 15% for the week, the largest weekly gain since October 2010, as frigid weather has increased demand for indoor heating across the Midwest and the East Coast. About […]