Stocks are opening flat on Wall Street Thursday. Losses by healthcare stocks such as Cardinal Health are holding back gains by consumer staples such as Kellogg, leaving indexes hardly changed from Wednesday's flat close. The Labor Department reported that U.S. productivity rebounded sharply in the first quarter. Other data showed unemployment aid fell last week to the lowest point since before the viral pandemic. European indexes fell in early trading Thursday while Japan's benchmark Nikkei 225 finished higher. The global recovery is raising hopes for improved exports and earnings of companies doing business overseas.