What is VIX Ref? VIX Ref is the price of the VIX at the time the SpotGamma data was calculated. Why does VIX Ref matter? A large change in VIX may mean that implied volatility has shifted significantly. How to use VIX Ref A higher VIX likely means options market makers have added short hedges which adds market selling pressure. A lower implied volatility means options market makers may add buying pressure. Related articles What is Total Call OI (Open Interest)? What is Top Put OI (Open Interest)? What is Gamma, Market Gamma and/or Total Market Gamma? What is Reference Price/Ref Price? What is Volatility Skew?