CBOE Volatility Index (VIX)
The CBOE Volatility Index (VIX) was introduced in 1993 by the Chicago Board of Options Exchange (CBOE), and it is now considered the benchmark for stock market volatility.
The VIX measures the market's expectation of 30-day volatility and is based on real-time S&P 500 index option prices. During periods of financial stress, which are often accompanied by steep market declines, option prices and the VIX - tend to rise. As investor fear subsides, option prices tend to decline, which in turn causes VIX to decline. It is important to note, however, that past performance does not necessarily indicate future results.