The VIX, or "fear gauge," measures expected stock market volatility over 30 days. A higher VIX suggests increased market stress and potential stock market declines. Stock market uncertainty from P ...

The Cboe Volatility Index, which trades under the ticker symbol VIX, was up more than 7% at around 43.68, according to FactSet data, at last check. That’s after jumping 21% on Thursday.