Volatility · Earnings
IV Crush Around Earnings: Why Options Lose Value After the Report
IV crush is the sharp drop in implied volatility once an expected event such as an earnings report has passed. Before the date, options price in a big jump and are expensive; afterwards the uncertainty is gone, and much of the time value goes with it. That is why a call can lose money after good results even though the stock rises: it rose less than the market had priced in.
By Daniel Berg ·
Stock after the report
+4%
- IV before the report
- 80%
- IV after
- 30%
- $100 call before
- $4.40
- $100 call after
- $4.30
Illustrative Black-Scholes values with round assumptions, not a real stock. Details in the worked example.
What is IV crush?
An option’s price is made up of intrinsic value and time value. How large the time value is depends heavily on implied volatility (IV), the movement the market expects over the option’s life. The higher the IV, the more expensive the option. Our guide How option prices work shows how the pieces fit together.
Ahead of a known event with an uncertain outcome, the IV of short-dated options rises. With earnings, everyone knows the day the stock may jump, but nobody knows which way or how far. That uncertainty is priced into the premium. Once the numbers are out, the event is history. IV often falls back to the level of an ordinary day within a single session. That is the crush.
How much a position is exposed is measured by vega: the change in the option’s price per percentage point of IV. Option buyers are long vega and lose in a crush; sellers are short vega and gain. Our implied volatility guide covers this in detail.
The mechanics: why IV rises before the event and falls after it
Think of the volatility until expiry as ordinary days plus one special day. The move expected on earnings day sits in full inside every option that expires after the report. For an option with a week left, that one day is a large share of the total expected movement; for an option with three months left, it is spread across many days.
- Short expirations are hit hardest. Their IV rises most before the event and falls furthest after it.
- The term structure gets a kink. The expiration right after the report carries much higher IV than the next one, which is easy to see in the options chain.
- The crush hits every strike. Calls and puts lose time value alike; the price move only decides whether intrinsic value makes up for it.
- Longer expirations lose less. For them earnings day is one day among many, so their IV drops only moderately afterwards.
The expected move: how much movement the market is pricing
The simplest way to read the priced-in jump is the straddle: the price of an at-the-money call plus put in the first expiration after the report. As a rule of thumb, that price roughly equals the move the market expects by expiry, in either direction. If the straddle on a $100 stock costs $8, the market is pricing about ±8%.
That is the key benchmark. An option buyer only wins after the report if the actual move is larger than the priced-in one. A seller wins if it is smaller. Direction alone does not decide it. Our earnings calendar shows the options market’s expected move for upcoming reports.
Worked example: right direction, still no profit
Black-Scholes values with round assumptions (zero rates, no dividend), not a real stock and not market data.
- Stock price
- $100
- Strike
- $100 (at the money)
- Time left
- 7 days
- IV before / after
- 80% / 30%
1Before the report
At 80% IV the call and the put each cost about $4.40. The straddle costs $8.80, so the market is pricing roughly a ±8.8% move.
2Good results, stock +4%
The stock rises to $104 and IV drops to 30%. The call is now worth about $4.30, slightly down despite the right direction. Had IV stayed at 80%, it would be worth about $6.50: the crush costs roughly $2.20 per share.
3The straddle
The put falls to about $0.30. Together the straddle is worth $4.60, about 48% less than the $8.80 paid. The 4% move was smaller than the 8.8% priced in.
4Stock unchanged
If the stock stays at $100, the call is worth only about $1.50 at 30% IV, a loss of roughly two thirds overnight.
5Stock +10%
If the stock jumps to $110, the call is worth about $10, and so is the straddle: a gain of a little over 13% on the straddle. Only a move larger than the expected move pays the buyer.
The rule of thumb: buying options before earnings is not a bet on direction but a bet that the move will be larger than priced in. Losses of 30% to 60% of the premium overnight are therefore nothing unusual for long options after earnings when the reaction is moderate.
Why option buyers lose so often after earnings
- They pay for the uncertainty up front. The elevated IV is the price of the possible big move. If it does not come, the money is gone.
- The expected move is often generous. Because sellers want to be paid for the risk of an outlier, the priced-in move frequently exceeds the actual one. That is not guaranteed.
- Short expirations magnify the effect. The options that look cheapest, with only days left, carry the highest IV before the report and lose the most afterwards.
- Theta and vega work together. After the report the option loses not only through the crush but also decays faster. Waiting for a recovery after a disappointing day keeps costing time value.
Strategies that benefit from IV crush, and their risks
Short-vega strategies collect the inflated premium before the report and profit when the move is smaller than priced in. The cost is the risk of an outlier.
| Strategy | Structure | Wins if … | Risk |
|---|---|---|---|
| Short straddle / strangle | Sell a call and a put | the stock stays within the premium | Unlimited or very large on a big jump |
| Iron condor | Sell a strangle, buy the wings | the stock stays between the short strikes | Capped at wing width minus premium |
| Iron butterfly | Sell a straddle, buy the wings | the stock closes near the strike | Capped, but a narrow profit zone |
| Calendar spread | Sell the short expiry, buy a longer one | short-dated IV falls more than long-dated | Capped at the premium paid; hurt by a big jump |
For most retail traders only defined-risk versions make sense. A naked short straddle can cost several times the premium collected on a 20% gap, and earnings gaps happen outside trading hours, where no stop can trigger. Set the position size and maximum loss before you enter; see risk management.
Checklist before trading through an earnings report
- 1Check the date: before the open or after the close? Which expiration is the first one after the report?
- 2Read the expected move (at-the-money straddle price) and compare it with the actual reactions over the last few quarters.
- 3Compare the short expiration’s IV with the next one: how large is the earnings premium?
- 4Decide whether you are betting on a larger (long vega) or smaller (short vega) move than priced in, not just on direction.
- 5Work out the maximum loss on a gap in either direction, including a move twice as large as expected.
- 6Set the exit: short-vega positions are usually closed soon after the open on the following day, once the crush has happened.
Frequently asked questions
What is IV crush in simple terms?
IV crush is the sharp fall in implied volatility after an expected event such as earnings. Before the date options are expensive because the market prices in a big jump. Afterwards the uncertainty is gone, IV drops and options lose much of their time value, often overnight.
Why did my call lose money even though the stock rose after earnings?
Because the stock rose less than the move that was priced into the premium. The gain in intrinsic value is eaten by the loss in time value when IV collapses. In this guide’s example the stock rises 4% and the call still slips, because 8.8% had been priced in.
How do I calculate the expected move before earnings?
As a rule of thumb, take the price of the at-the-money straddle, a call plus a put at the same strike, in the first expiration after the report. Divide it by the stock price to get the priced-in move in percent, in either direction. The BeInOptions earnings calendar shows this figure for upcoming reports.
How much does IV drop after earnings?
It varies by stock and by quarter. For short-dated options a drop of half or more is not unusual, while longer expirations lose much less. There is no fixed number; compare the IV of the expirations before and after the report to estimate the earnings premium.
Which strategies benefit from IV crush?
Strategies that sell options and are short vega: the iron condor, iron butterfly, short strangle or calendar spread. They win when the stock moves less than priced in. Versions with long wings cap the loss on a big jump and are the more sensible choice for most traders.
Can I avoid IV crush as a buyer?
Not entirely, but you can reduce it: with debit spreads, where the sold leg partly offsets the crush, with longer expirations whose IV falls less, or by entering after the report, once IV has already dropped. Each option trades some profit potential for less vega risk.
Where to go next
All numerical examples in this guide are rounded, illustrative assumptions, not market data. The content is educational and not investment advice. Options are complex instruments; you can lose the entire amount invested, and more than that when selling options.