Shares of Walmart Inc. dropped in morning trading Thursday after the discount-retail behemoth missed fiscal second-quarter profit expectations but raised its full-year outlook and saw strength in sales at its retail as well as its Sam’s Club warehouse stores.

U.S. stocks are falling again, this time after the country’s largest retailer reported profits that came up short of Wall Street’s expectations. The S&P 500 fell 0.5% in early trading Thursday and was on track for a fifth straight modest loss since setting an all-time high last week.