Traders are backing off their bearish bets on natural-gas prices, stock buyers are flocking to the beaten-down shares of Appalachian producers and analysts are forecasting short supplies of the fuel next year unless those companies get back to drilling. All this comes with natural gas fetching its lowest price in a quarter-century and a global pandemic crushing demand from power plants and factories. It is also spring, when heating demand from U.S. households typically falls off a cliff. …