Implied volatility (IV) of a stock's options typically rises 30-100% in the week before an earnings announcement, peaks the day before, and crashes back to normal levels within hours of the release. This "IV crush" can make a directionally correct options bet a money loser. Example: Stock X is at £100 with earnings tomorrow. IV is 75%. You buy a £105 call with 14 days to run for £3.90. After earnings the stock rises to £104 and IV crashes to 30%. Re-priced, your call is worth £1.95 — you lose half the premium despite a 4% move in your favour, because the option needed roughly £107.40 just to break even once the volatility left it. The correct strategy for trading earnings is to sell premium, not buy it (iron condors, strangles, etc.), or simply avoid earnings entirely until you understand IV mechanics.
This page gates Level 2 — Structure
IV crush is the clearest lesson in the second tier of the strategy curriculum: a correct directional call can still lose money. Before you open any multi-leg trade around an event, you should be able to tick every item on this list from this page alone:
- The mechanic. Implied volatility rises 30-100% into earnings, peaks the day before, and collapses within hours of the release — and the extrinsic value of every option goes with it, via vega.
- What crush does to a long option. In the worked example below, a £3.90 call re-prices to £1.95 after the stock moves 4% in its favour, because the post-crush breakeven sat 7.4% away. Right on direction, down half the premium.
- The implied move. Read it from the at-the-money straddle. A long option held through the release only wins if the stock moves more than the implied move.
- Why sellers own the event. Defined-risk premium selling — the iron condor and iron butterfly — profits from the crush, with the maximum loss capped by construction at the spread width minus the credit, times the contract multiplier.
- Where the line is. A short straddle with no protective wings is undefined risk, and an earnings gap is exactly the event that punishes it. It is not a retail earnings trade.
You are ready for Level 2 when… you can explain why a directionally correct long option lost money after earnings, and can price the defined-risk structure you would sell instead. Then open Level 2 — Structure.
The mechanic of IV crush
Option pricing has two components: intrinsic value (in-the-money portion) and extrinsic value (time + volatility premium). Implied volatility (IV) is the market's expectation of future price movement, embedded in the option premium.
Before earnings:
- Stocks have uncertain outcomes — the announcement could move the price 5-20%.
- Options market participants bid up extrinsic value to compensate for this risk.
- IV often doubles from baseline (e.g. 30% to 60%).
After earnings:
- The uncertainty is gone — the result is now known.
- Extrinsic value collapses as IV resets toward baseline.
- The IV reduction translates directly to option price reduction (via Vega).
Worked example — the crush in action
Stock X earnings — directional play gone wrong
Stock X is at £100. Earnings tomorrow. IV is at 75% (elevated for earnings).
You buy a £105 call expiring in 14 days for £3.90 — £390 for one contract. At those inputs the model puts delta at 0.40 and vega at £0.076 per volatility point (£7.60 per contract per point).
Earnings: the stock rises from £100 to £104 (+4% — a real move in your direction) and IV falls back to 30%.
| Premium paid (£105 call, 14 days, IV 75%) | £3.90 |
| Intrinsic value at entry (the £105 strike is above the £100 spot) | £0.00 |
| Extrinsic value at entry — 100% of the premium | £3.90 |
| After the release: spot £104, 13 days left, IV 30% | |
| Intrinsic value now (still below the £105 strike) | £0.00 |
| Re-priced with Black-Scholes | £1.95 |
| Your option is now worth £1.95, you paid £3.90 | −£1.95 (−50%) |
You were right on direction and still lost half the premium. At the post-crush inputs the stock had to finish above roughly £107.40 — a 7.4% move — simply to get your money back, and the 14-day at-the-money straddle was pricing an implied move of about 11.7% when you bought. A 4% result was never going to be enough.
Why you cannot do this with vega alone. Vega is a local first derivative, not a licence to extrapolate. Multiplying it across a 45-point volatility collapse gives 45 × £0.076 = £3.42, which here is roughly the £3.25 the crush actually costs if the stock does not move at all — but on other inputs the same arithmetic hands you a "loss" bigger than the entire premium, which cannot happen. Re-price the option; do not multiply out the Greek.
Move the stock further and the arithmetic flips: at £108 the same call re-prices to about £4.30, a £0.40 gain. IV crush does not make a directional bet unwinnable — it pushes the break-even a long way past where most people assume it sits.
Prices above are Black-Scholes with a 4% risk-free rate and no dividend: £3.88 at entry and £1.96 after the release, rounded to the nearest 5p.
What you need to know about earnings before trading
- Look at the implied move. The options market prices an "expected move" based on the price of at-the-money straddle. If the straddle is £4 and stock is £100, the implied move is 4%. The stock needs to move MORE than the implied move for a long option to profit after IV crush.
- Historical post-earnings moves. Look at the last 4-8 earnings releases. Did the stock typically move more or less than implied? Stocks with consistent "beats" tend to move more; "miss-prone" stocks move less.
- Time to release. IV peaks in the final 1-3 days before earnings. Buying options 30 days out and selling them the day before earnings (avoiding the crush) is a common pre-earnings strategy.
The right way to play earnings — sell premium, don't buy
If you believe the implied move is overpriced (the market is too uncertain), sell premium via defined-risk strategies:
- Iron condor: sell an out-of-the-money call AND an out-of-the-money put, buy further-OTM call and put for protection. Profits if the stock stays in a wide range.
- Iron butterfly: sell an at-the-money straddle, buy wings for protection. Profits if the stock stays near the current price.
Both of those are defined-risk: the long wings cap the loss, and the maximum loss is (width of the wider spread − net credit received) × the contract multiplier, 100 on a US contract and 1,000 on a traditional ICE UK series. You know the worst case before you open, and it is usually several times the credit you took in.
These strategies profit from IV crush. If IV drops 50% and the stock stays roughly flat, you collect most of the premium received.
Undefined risk — not in the list above
A short straddle (selling both the at-the-money call and the at-the-money put with no protective wings) is sometimes suggested as an earnings trade. It is not a defined-risk strategy and does not belong in the list above: loss on the call side is theoretically unlimited, loss on the put side runs to the strike, and an earnings gap is exactly the event that produces both. It requires high options approval and substantial margin, and it is not a retail earnings trade. If you want the same short-volatility exposure with a floor under it, buy the wings and trade the iron butterfly instead.
The "earnings calendar" approach
Track earnings dates for your watchlist. For each upcoming earnings:
- Note the date and time (UK: usually evening US time = morning UK time next day).
- Check the implied move (from current at-the-money straddle).
- Compare to historical moves (look at past 4-8 quarters).
- Decide your stance: bullish, bearish, or neutral.
- Choose strategy:
- Strong directional view + large expected move: long call/put 30+ days out (close before earnings to avoid crush).
- Neutral or "implied move is overpriced": iron condor or iron butterfly.
- No view or "implied move looks fair": stay out.
Common earnings-trading mistakes
- Buying long options the day before earnings. You're paying peak IV. The crush will hit you. Almost always loses money.
- Selling naked options into earnings. A 20% gap move could wipe out years of premium income.
- Trading meme stocks through earnings. Implied moves are often 10-15% but actual moves can be 30%+. The risk-reward is gambling-grade.
- Forgetting time of release. Most US earnings are after market close (US time) — moves happen overnight. By the time you can react, the move is done.
- Ignoring sector spillover. A bad NVDA earnings can drag down AMD, INTC, semis broadly. Be aware of correlated positions.
The retail conclusion
For most UK retail options traders: don't trade earnings for your first 12 months. Trading through earnings (holding a covered call position through earnings, for example) is acceptable if the position was opened before IV elevated. Opening new long positions in the week before earnings is almost always a losing strategy at retail size.
If you must trade earnings, use defined-risk premium-selling strategies (iron condors, butterflies) — not long calls or puts.
Sources and methodology
IV crush observations are based on standard options-pricing theory (Black-Scholes + extensions) and empirical data from broker-published implied volatility surfaces. The worked example above is priced with the Black-Scholes formula (4% risk-free rate, no dividend) rather than by extrapolating vega, because vega is a first derivative that is only valid locally — see the Options Industry Council on understanding options Greeks. For a personalised options strategy, see the tax adviser editorial recommendation (regulated investment advice requires FCA authorisation). The methodology page documents sources.
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