Wall Street Fear Index Creeps Up as Investors Assess Iran Strikes

The most widely-followed barometer of market volatility ticked up on Monday, as investors tried to make sense of how the crisis in the Middle East will impact stocks.

The Cboe Volatility Index, or VIX, rose 0.3 points to just under 21 ahead of the U.S. opening bell. The fear gauge tracks S&P 500 options contracts to measure traders' stress levels. Any reading of above 20 tends to indicate relatively high volatility.

The VIX was creeping higher after the U.S. bombed three key nuclear sites in Iran over the weekend, fueling concerns that Tehran could retaliate in a way that drives up oil prices. Investors were overlooking those fears on Monday, though, with stock futures a touch higher and crude benchmarks headed for modest gains.