The volatility index, or VIX, gained 32% today.
The VIX, commonly referred to as the "fear index," measures expected volatility in the S&P 500 over the next month.
Amid the Malaysia Airlines plane crash in Ukraine and late afternoon reports that Israel has begun a ground operation in Gaza, stocks sold off as "safe haven" assets like gold and bonds rallied.
Gold was trading near $1320 an ounce, up from about $1305 early in the day, while the yield on U.S. 10-year Treasury bonds fell to 2.44% from 2.51% earlier.
The VIX, which has been at historically low levels through the spring, traded up to 15.00 - or an advance of more than 37% - at one point during the session before settling at 14.54.
Here's a chart of today's action.
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