Weak data reignited fears of an economic slowdown, and U.S. stocks "opened the door to darkness" in September

New economic data reignited concerns about the health of the economy, with U.S. stocks off to a rocky start to September and technology stocks collectively tumbling. The Dow fell more than 650 points, or 1.6 percent, during the session. The S & P 500 fell more than 2.2 percent, while the fear gauge VIX surged 30 percent. The Nasdaq fell 3.3 percent, its worst day since the Aug. 5 global stock market rout. Shares in artificial intelligence darling NVIDIA (NVDA. O), which has been on investors' radar for more than a year, fell more than 9 percent, leading semiconductor stocks to pressure the stock market. Earlier data showed that the final U.S. S & P global manufacturing PMI fell in August, while the U.S. ISM manufacturing index in August also missed economists' expectations. Larry Tentarelli, chief technology strategist at Blue Chip Trends, said: "The market seems to be very sensitive to any data right now." "We've become a very data-dependent market."