Zoom Video Communications Inc ZM.O tumbled 11.5% after the pandemic favorite cut its annual profit and revenue forecasts. The S&P Global flash composite purchasing managers index for August dropped to 45 this month, the lowest since February 2021, from a final reading of 47.7 in July. Wall Street closed sharply lower in the past two sessions as investor focus turned to a Fed gathering later this week in Jackson Hole, where central bank Chair Jerome Powell is expected to reinforce a strong commitment to stamp out inflation running at four-decades high.