Core concept
What is IV crush?
IV crush is the repricing that happens when implied volatility falls, usually after a known uncertainty is resolved. Because implied volatility is embedded in option premiums, a lower IV can reduce extrinsic value even if the stock price moves.
Why it happens
Before events, traders may pay more for optionality because the next move is uncertain. After the announcement, the unknown becomes known. Demand for protection or speculation can fade, market makers can reprice risk, and the volatility component of premium can contract.
uncertainty high
price gaps
IV resets
What IV crush is not
It is not proof that the trade was bad, not a dependable post-earnings pattern, and not a complete pricing model. It is one major component of option value that should be isolated before entering long or short premium trades.
Primary reading: OIC implied volatility overview · OIC Vega guide · OIC volatility and Greeks · FINRA options basics and Greeks · SEC Investor Bulletin on options