IV Rank vs Vega

A measure of current implied volatility relative to its 52-week high and low; calculated as (current IV − 52-week low) / (52-week high − 52-week low) × 100; IV Rank above 50 indicates elevated premium; IV Rank below 30 indicates compressed premium, favoring different options strategies.

The rate of change of an option's price relative to a 1% change in implied volatility; long options have positive vega (gain value when IV rises); short options have negative vega (lose value when IV rises); the primary risk in bought options around anticipated events.