Ill-timed bets on rising demand have Exxon Mobil Corp facing a shortfall of about $48 billion through 2021, according to a Reuters tally and Wall Street estimates, a situation that will require the top U.S. oil company to make deep cuts to its staff and projects. Wall Street investors are even starting to worry about the once-sacrosanct dividend at Exxon, which in the 20th Century became the world’s most valuable company using global scale, relentless expansion and strict financial controls. Exxon weathered a series of setbacks last decade and under Chief Executive Darren Woods sought to return to past prominence by big bets on U.S. shale oilfields, pipelines and global refining and plastics. It also bet big on offshore Guyana, where it discovered up to 8 billion barrels of oil, six years of production at its current rate. But Exxon’s ability to finance that global expansion […]