The halts came as the Cboe Volatility Index VIX, better known as the VIX or Wall Street's "fear gauge," tallied its biggest daily drop on record, according to Dow Jones Market Data. The iPath ...

The Cboe Volatility Index, an options-based gauge of expected volatility in the S&P 500 widely known by its trading symbol, VIX, jumped Monday morning to its highest level since December.