“A strong dollar is going to hurt exports and the revenue line of companies, which wasn’t strong to begin with,” said Rick Fier, director of trading at Conifer Securities in New York. The buoyant data comes after Federal Reserve Chair Janet Yellen said on Friday that the central bank could raise interest rates this year if the economy keeps improving as expected. Yellen’s comments and the dollar’s rise pushed the monthly gain for each of the three major U.S. stock indexes to below 2 percent in the past two trading sessions.