The U.S. stock market opened mostly lower Thursday, as investors digested a fresh reading on wholesale inflation and weekly jobless claims data. The Dow Jones Industrial Average DJIA was down 0.5% soon after the opening bell, while the S&P 500 SPX fell 0.2% and the Nasdaq Composite COMP gained 0.1%, according to FactSet data, at last check. The producer-price index, a measure of wholesale inflation in the U.S., rose 0.2% in April, according to a Department of Labor report Thursday. That’s slightly below the 0.3% rise forecast by economists polled by The Wall Street Journal. Meanwhile, initial jobless claims rose to 264,000.