The Cboe Volatility Index jumped on Thursday, putting it on track for its biggest one-day move in about a month. The VIX rose 11.8%, or 1.89 point, to 17.86. At current levels, the day's move would represent its biggest gain since April 6. The rise was just the latest example of heavy day-to-day volatility in Wall Street's so-called "fear index," which uses S&P 500 options to calculate expectations for volatility over the coming 30 days. It is up more than 61% thus far this year, although that gain is from historically low levels. Currently, it remains below its long-term average between 19 and 20. Thursday's rise came as stocks fell broadly; the Dow Jones Industrial Average fell 1.4% to 23,584, which would represent its lowest close in March 23. The S&P 500 fell 1.4% while the Nasdaq Composite Index fell 1.3%. Both the Dow and the S&P dropped below their 200-day moving averages.