Billionaire hedge fund manager David Einhorn, who often moves a stock simply by speaking its name, on Monday kicked off the year’s most prominent investment conference by laying out a case against oil frackers, arguing these companies drill “lots and lots of holes” and burn through plenty of cash. Einhorn, who often unveils short-bets against companies at these events, cited Pioneer Natural Resources Co as a particular offender at the 20th annual Sohn Investment Conference.