Major U.S. stock indexes appeared set to open in the green on Wednesday. S&P 500 futures rose 0.25% in pre-market trading, the Nasdaq moved up 0.4%, and the Dow Jones Industrial Aveerage just nudged into positive territory after solid gains on Tuesday. Following last week’s volatility, this week’s mostly consistent positive trading looked set to allow investors a long, pleasant holiday week and weekend. But beneath the placid surface, surprising news made ripples across major sectors — from usually quiet ...