The Cboe Volatility index spiked Thursday afternoon, reaching the highest level in more than eights months as the main U.S. benchmarks convulsed lower. The so-called fear index gained more than 12% to reach an intraday peak of 28.84, marking the highest level for the gauge since Feb. 9 when it hit 29.06, according to FactSet data. Thursday's move comes after a 44% surge for the volatility gauge on Wednesday, which coincided with an 831-point tumble for the Dow Jones Industrial Average . The moves have taken the VIX, which uses S&P 500 options to calculate expectations for volatility over the coming 30 days, well above its long-term average around 20. The gauge typically falls as as stocks rise, and vice versa. Thursday stock trading extended Wednesday's bloodbath. The Dow traded down 699 points at session lows, down 2.7%, while the S&P 500 index was down by more than 2%, and the Nasdaq Composite Index was facing a more than 1% drop.