What is IV Crush? Definition, Formula, and Example
IV crush is the rapid collapse of implied volatility and option premiums that occurs immediately after a binary event — an earnings release, FDA decision, or Fed announcement — is resolved, often causing options buyers to lose money even when their directional call was correct.
What Is IV Crush?
IV crush is the rapid collapse of implied volatility — and therefore option premiums — that occurs the moment a significant binary event is resolved. Before earnings, FDA rulings, or Federal Reserve decisions, implied volatility inflates because the outcome is uncertain. The moment the outcome is known, that uncertainty vanishes and IV reverts sharply lower, often collapsing 50–70% within minutes of the market open. Options holders on the wrong side of this dynamic lose premium even when they are right on direction.
How It's Calculated
The dollar impact of IV crush on an open options position is quantified through vega:
Premium loss from IV crush = Vega × (IV_before − IV_after)
Where IV is expressed in percentage points. If a call has a vega of 0.18 and IV drops from 72% to 28% after earnings — a 44-point collapse — the option loses $7.92 per contract purely from the volatility decline, before any delta-driven price move is considered.
The market-implied expected move heading into an event is embedded in the ATM straddle:
Expected Move ≈ ATM Call Premium + ATM Put Premium
If a $210 stock has a straddle priced at $10, the market is pricing in a ±$10 (4.8%) move. If the stock moves exactly $10 but IV crushes from 72% to 28%, the straddle buyer still loses because the vega loss exceeds the delta gain.
Worked Example
Before AMZN Q4 2025 earnings, shares trade at $210. The at-the-money $210 call expiring 5 days out is priced at $9.40, with IV at 72% and vega at 0.18. AMZN reports strong results and gaps up 4% to $218.40 on the open. IV drops immediately to 28%.
- Delta gain ≈ 0.50 × $8.40 = $4.20
- Vega loss = 0.18 × (72 − 28) = $7.92
- Net P&L = −$3.72
The trader called direction and magnitude correctly and still lost on the trade. This is the defining feature of IV crush: the volatility collapse overrides the directional profit.
When Traders Use This Concept
Understanding IV crush determines whether to buy or sell premium ahead of events:
- Selling premium before earnings — credit spreads, iron condors, and strangles profit from IV crush when the stock stays within the implied move range
- Comparing implied vs. historical move — if a stock's straddle prices in a ±6% move but it has realized ±3% on the last eight earnings, selling the straddle has positive expected value
- IV Rank screening — confirm IV is elevated relative to its own 52-week range before selling premium; IV Rank above 50 is the standard threshold
- Avoiding long premium into events — buying calls or puts ahead of an anticipated catalyst without accounting for IV crush is one of the most common options trading errors
Limitations and Common Misconceptions
IV crush is not guaranteed. A severe earnings miss or unexpected guidance cut can keep IV elevated or push it higher post-announcement, particularly in small- or mid-cap names with low analyst coverage. Debit spreads reduce IV crush exposure by partially offsetting vega across both legs, but do not eliminate it. Far out-of-the-money options carry near-zero vega and feel minimal absolute dollar loss from IV crush, but the percentage wipeout of premium can still be severe if the stock fails to reach the strike. The straddle-implied expected move is a probabilistic range, not a price target or floor — stocks routinely move far less than implied, making straddle purchases wrong on both vega and delta.