As the CBOE Volatility Index, the so-called fear index, slides below a one-year low, VIX exchange traded product traders could begin to see volatility tick higher in a complacent market.

The VIX, an options-based measure of expectations for price swings in the S&P 500 index, was hovering around 11.6 Friday, after dipping to as low as 11.46 in early trading, its lowest level since March 2013. The low reading reflects the low volatility or greater complacency in the equities market.

Inverse VIX-related ETFs such as the VelocityShares Daily Inverse VIX Short-Term ETN (NYSEArca: XIV) and ProShares Short VIX Short-Term Futures ETF (NYSEArca: SVXY) strengthened 0.5% and 0.7%, respectively Friday. The two have gained about 15.2% over the past month. [Inverse VIX ETF Bets Pay Off on Waning Market Volatility]

“The market’s been lulled to sleep,” J.J. Kinahan, chief strategist at TD Ameritrade, said in a Wall Street Journal article. “At the end of the day, [stocks]haven’t really gone anywhere for most of this year.”

The VIX typically moves higher when stocks plunge. Investors would turn to S&P 500 options to protect their portfolios against any sudden dips.

While the VIX has been steadily declining on a more sanguine outlook in the S&P 500, volatility has increased in small-cap stocks. The S&P 500 is trading around its all-time high, but the Russell 2000 has dipped 7.6% from its own record high in March.