U.S. stocks tumbled on Thursday to end sharply lower, with the S&P 500 posting its worst daily decline since mid-September. The Dow Jones Industrial Average /zigman2/quotes/210598065/realtime DJIA -0.48% shed about 1.5%, or roughly 457 points, ending near 29,226, after falling more than 600 points at the session's low. The S&P 500 index /zigman2/quotes/210599714/realtime SPX +0.02% closed down 2.1%, marking its worst daily percentage decline since Sept. 13 when it tumbled 4.3%, according to FactSet data. The tech-heavy Nasdaq Composite Index /zigman2/quotes/210598365/realtime COMP +0.26% bore the brunt of the day's selling among the three major equity benchmarks, declining 2.8%. Investors were reacting Thursday to a flurry of economic data that suggested no letup in the Federal Reserve's plans to keep increasing rates to fight inflation. That included a weekly report on U.S. jobless benefit claims showed the number of Americans initially applying for unemployment benefits fell to 193,000 in the week ended September 24, the lowest level since April. Apple Inc /zigman2/quotes/202934861/composite AAPL +0.45% shares also were in focus for a second trading day, booking a 4.9% decline and pulling down the Dow.