Stock market investors who spent January swayed by oil prices, economic weakness in China and central bank speculation may continue to do that next week, even though it should be a dramatic one for earnings reports and economic data. Fourth-quarter 2015 earnings reports coming from Internet leader Alphabet (GOOGL.O) and Exxon Mobil (XOM.N), an old-economy company hit by falling oil prices, will spotlight the yin and yang of Corporate America.