New York Times: Exxon Mobil is the biggest publicly traded company in the world, but its stock price has been lagging over the last year chiefly because a lot of people wonder why it’s making such a big bet on natural gas. Exxon Mobil spent $41 billion a year ago to acquire XTO Energy, doubling its natural gas reserves. And it is building up a massive liquefied natural gas capacity around the globe. Too bad for Exxon Mobil that a gas glut in the United States and elsewhere is causing gas prices to tank, and a…