FedEx Corp. slashed profit projections for 2012 after posting another quarterly slump in earnings, and its chief executive said trade has slowed to levels not seen during the last two significant economic downturns. That's not exactly what Wall Street wants to hear from a company considered to be a bellwether of the global economy. And it also portends bad news for the hundreds of major U.S. companies that will start reporting third-quarter earnings in a few weeks.