Federal Reserve officials are playing it cool for now, but roughly $2.5 trillion of stock market value wiped out in the past three weeks and a possible consumer pullback could throw the Fed off its course of gradual interest rate hikes. Policymakers continue to argue that the threat will pass, but the risk that the selloff will hit the main engine of U.S. economic growth – household spending – gets bigger the longer markets remain depressed. Fed policymakers meet on Tuesday and Wednesday for the first time since raising interest rates in December.