IV Rank vs Vol Crush

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 rapid compression of implied volatility that frequently occurs immediately after a highly anticipated event resolves; causes bought options to lose vega value even when the price move was favorable; the primary reason option buyers around events often lose money despite being correct on direction.