The Cboe Volatility Index® (VIX® Index) is widely considered the proxy for market sentiment in the U.S. equity market. VIX measures the 30 day expected volatility on the S&P 500® Index (SPX).
Cboe’s Russell 2000 Volatility Index℠ (RVX℠) applies the same methodology for calculating 30 day anticipated volatility, but it uses Russell 2000 Index options. (RUT). As such, RVX is considered the benchmark proxy for 30 day expected volatility of U.S. Small-caps.