IV crush around earnings: the trade inside the trade

Earnings · 6 min read

Why a straddle can lose on a big earnings gap: implied volatility crush, the pre-event ramp, and how to weigh the expected move against the priced move.

Buying options into earnings feels like the cleanest trade in the book: something big is about to happen, options profit from big moves, so buy options. Then the stock gaps 6% in your direction and your straddle loses money anyway, and the whole enterprise feels rigged. It isn't rigged, it's priced. Every earnings option trade is really two trades stacked on top of each other: a bet on the size of the move, and a bet against the collapse in implied volatility that follows the announcement. Most traders only know they placed the first one.

Why implied volatility inflates before the report

An earnings date is scheduled uncertainty. Everyone knows that on one specific evening, the stock will reprice, maybe 4%, maybe 9%. Option sellers demand compensation for standing in front of that gap, so implied volatility on contracts spanning the event climbs steadily in the days before. A stock that normally trades at 28 implied volatility might see its front-weekly options bid up to 65 or 80 by the afternoon of the report. That elevated number is not a forecast error. It is the market's consensus price for one night of gap risk, and it is usually a fairly honest one.

The moment the numbers hit the tape, the uncertainty is resolved, whatever the outcome. There is nothing left for that elevated implied volatility to insure. So it collapses, typically within minutes of the next open, from event levels back toward the stock's ordinary baseline. Traders call it the crush. It is not an anomaly; it is the event premium being refunded to whoever was short it.

Figure: The crush: elevated implied volatility carries the option price into the report; at the next open the event premium reprices away, and the gap has to out-earn the drop.

A worked example: right about the move, wrong about the trade

The setup: a stock trades at $200 the afternoon before earnings. You buy the at-the-money straddle, the $200 call and $200 put expiring in three days, for a combined $11.40. Implied volatility on those contracts is 78. That $11.40 is the market saying: we expect roughly a 5.7% move, and this is what one night of it costs.

The result: earnings beat, and the stock gaps up 6% to $212. A bigger move than the straddle implied. You were right. Now the accounting:

The call is $12.00 in the money, but implied volatility has crushed from 78 to 34. With almost no time left and the event premium gone, the call trades near $12.55, intrinsic value plus scraps.
The put is $12.00 out of the money with two days to expiry at 34 volatility. It trades near $0.15.
Straddle value: $12.70. Cost: $11.40. Profit: $1.30 per share, or $130 per straddle, an 11% gain that required a 6% overnight gap in a single stock to achieve.
Now rerun it with a 4% move to $208: the call trades near $8.60, the put near $0.35, straddle worth $8.95, a loss of $2.45 per share, or $245 per straddle, on a move most people would call huge.

That is the trade inside the trade. Your Delta and Gamma made money on the gap in both scenarios. Your Vega lost roughly $500 of value the instant the event premium evaporated, because you were carrying several dollars of pure event volatility that repriced to zero at the open. The stock's move had to out-earn that guaranteed Vega loss just to reach breakeven. A 6% gap barely managed it. A 4% gap, still double the stock's normal daily range, did not come close.

It isn't rigged, it's priced. Every earnings option trade is really two trades stacked on top of each other.

The breakeven nobody calculates

Before any earnings options trade, do one piece of arithmetic: the straddle price as a percentage of the stock price is the market's implied move. If the straddle costs $11.40 on a $200 stock, the market has priced 5.7%. Owning that straddle is a bet the move exceeds 5.7%, not a bet that 'something happens.' Historically, most stocks move less than their implied earnings move most of the time, which is precisely why systematic pre-earnings option buying bleeds money despite the occasional spectacular winner. The sellers are not smarter; they are simply on the paid side of a fairly priced insurance contract.

Structures that acknowledge the crush

Once you see the two stacked trades, you can choose which one to take:

To bet on a bigger-than-implied move, accept that you are fighting the crush and size for the real breakeven, not the emotional one. You need the gap to beat the implied move, not merely to exist.
To bet on a smaller-than-implied move, short-premium structures with defined risk, such as an iron condor around the implied-move boundaries, are explicitly long the crush and short the gap. The one bad night defines the risk.
To bet on direction while muting the crush, spreads help: buying one option and selling another means the crush hits both legs, and much of the Vega loss nets out. A call spread bought for $3.10 keeps far more of its value through the crush than a naked call at the same strikes.
To bet on the crush itself while dodging the gap, calendar structures, short the event-week option against a longer expiry, isolate the front leg's inflated volatility. The later leg's volatility deflates too, just less.

Attribute the aftermath

Whatever you traded, decompose the result the next morning. Split the P&L into the Delta and Gamma contribution from the gap and the Vega contribution from the crush, and you will know which bet paid and which one collected from you. Traders who run this attribution a few times stop saying 'earnings trades don't work' and start saying something more useful: 'I was long the move and short the crush, and the crush was bigger.' That sentence contains an actual lesson. The account balance alone never does.

Educational content, not investment advice. Options involve substantial risk.