Users can toggle the Compare Mode, which enables a comparison of the Implied Volatility changes between two selected dates. The Reference Date is defaulted to the current date, and you can choose to compare it to a previous date, which you can choose in the Comparison Date field.

This view will show you how Implied Volatility has shifted from the comparison date to the reference date for a given security. Red coloration indicates a decrease in Implied Volatility, and green indicates an increase in Implied Volatility.