You're already familiar with financial yardsticks like the GDP, NYSE, AMEX and S&P. You may now want to keep an eye on something called the '"fear index."
The Chicago Board Options Exchange publishes a volatility index, or VIX. Introduced in 1993 by a Duke University professor, the fear index forecasts the market's volatility over the next 30 days. Additionally, CBOE has begun publishing a new tail-risk benchmark. "Tail risk" is the term investors sometimes use for the possibility that markets could experience a sudden and steep drop, not unlike the financial crisis in 2008.
Last week, the CBOE Market Volatility Index jumped as much as 9 percent to its highest level since mid-March, when the nuclear catastrophe in Japan became front page news. The VIX hit 25 on Friday. A reading of 30 is typically considered a fear tipping point.