A volatility threshold tells you whether the premium on offer is rich enough to write at all. It does not tell you where on the curve to write it. On the illustrative surface below, implied volatility rises all the way out to the far wing, but edge after costs peaks in the middle of the wing and then falls, credit per dollar of requirement collapses by a factor of eleven, and the real chance of finishing in the money is consistently worse than delta implies. Taken together, the risk-adjusted premium sits nearer the money than the win-rate intuition suggests.
A volatility threshold answers one question: is the price being offered rich enough, relative to a forecast of realised volatility, to justify writing anything at all. It is a gate. It says yes or no. It does not say where on the strike ladder the answer applies, and treating a single threshold as though it selected a strike for you is one of the more expensive category errors in options selling.
The intuition almost everyone brings to the strike question is that the far strike is the safe one. That intuition is half right, and the half that is right is what makes the other half so costly.
What is genuinely true about a far strike
Three things hold up. The probability of a claim really is lower the further from the money you write. The win rate really is higher. And because of volatility skew, the implied volatility attached to the far strike really is richer in relative terms than the implied volatility attached to a strike near the money.
Everything people go on to infer from those three facts is where the trouble starts. A higher win rate is not a higher expected result. A richer implied volatility per unit of distance is not more money. A lower probability of a claim is not a smaller claim.
An illustrative comparison across the strike ladder
The table below is illustrative. It prices 45 day put spreads on XSP with a 15 point wing, taken off a surface that includes its own skew, against a forecast of 14 per cent realised volatility. Every column is computed from the same snapshot, so the strikes are directly comparable with one another. The figures are inputs to an argument, not recommendations, and a reader substituting their own forecast, their own cost assumptions and their own loadings would get different rows.
| Short strike | Strike | Implied volatility | Credit | Probability in the money | Requirement, Reg T | Credit per unit of requirement | Edge after costs | Edge per unit of worst case | Threshold | Decision |
|---|---|---|---|---|---|---|---|---|---|---|
| 40 delta | 585 | 16.3% | $436 | 42.7% | $1,064 | 41.0% | -$40 | -3.8% | 19.9% | declined |
| 30 delta | 576 | 16.9% | $314 | 33.1% | $1,186 | 26.5% | -$9 | -0.8% | 19.1% | declined |
| 22 delta | 568 | 17.5% | $230 | 25.8% | $1,270 | 18.1% | +$16 | 1.2% | 19.1% | declined |
| 16 delta | 561 | 18.1% | $171 | 20.6% | $1,329 | 12.9% | +$29 | 2.2% | 19.2% | declined |
| 10 delta | 552 | 18.9% | $116 | 15.3% | $1,384 | 8.4% | +$39 | 2.8% | 19.7% | declined |
| 5 delta | 541 | 20.1% | $71 | 10.6% | $1,429 | 5.0% | +$37 | 2.6% | 21.6% | declined |
| 3 delta | 534 | 20.9% | $52 | 8.5% | $1,448 | 3.6% | +$32 | 2.2% | 26.3% | declined |
Read the 3 delta row across, because it is the row that most closely matches the popular picture of a safe trade. The 534 strike carries the richest implied volatility on the ladder at 20.9 per cent, and the lowest probability of finishing in the money at 8.5 per cent. It also produces a credit of $52 against a Reg T requirement of $1,448, which is 3.6 cents of credit for every dollar committed, and it faces the highest threshold on the ladder at 26.3 per cent. On this snapshot every row is marked declined, because the implied volatility on offer does not clear the threshold at any strike.
Four forces, pointing in different directions
Implied volatility rises monotonically as you move out. It runs from 16.3 per cent at the 40 delta strike to 20.9 per cent at the 3 delta strike. That is the skew, and it is the entire empirical basis for the belief that the far wing is where the money lives. Per unit of distance from the money, you are indeed being paid more.
Edge after costs does not rise monotonically. It peaks in the middle of the wing, at the 10 delta strike, and falls away on either side. Past that point the premium is thin enough that trading friction and the loading for tail risk consume it faster than the skew replaces it. The far wing is where the volatility number is highest and where the money left over is not.
Margin efficiency collapses, and it collapses hard. Credit per dollar of requirement falls from 41.0 per cent at the 40 delta strike to 3.6 per cent at the 3 delta strike. Eleven times worse. To collect a comparable amount of premium at the far strike you must commit roughly eleven times the capital, which means eleven times the exposure to the correlated event, meaning the single day on which every strike on that ladder is breached inside the same hour. Diversification across strikes is not diversification when the thing that breaches them is one move in one index.
The probability of a claim is consistently worse than delta suggests. The 16 delta strike finishes in the money 20.6 per cent of the time on these inputs, not 16 per cent. Delta is a hedge ratio, not a probability, and the gap between the two runs against the seller rather than for them. The relative size of that error is larger at the far strikes, which are precisely the strikes people select because the delta looked comfortable.
The honest conclusion, and its own failure mode
Put the four together and the conclusion is neither "write the far strike" nor "write the near strike". It is that the risk-adjusted premium sits nearer the money than the win-rate intuition suggests, and that the capital efficiency argument happens to point in the same direction. The far wing is not free money guarded by a low probability. It is thin money guarded by a low probability and paid for with a great deal of capital.
That conclusion has a failure mode of its own, and it deserves stating at the same length. Moving nearer the money buys efficiency at the cost of frequency. The 40 delta row finishes in the money 42.7 per cent of the time, so claims arrive often, and a book written there generates a long sequence of paid losses that must be funded from somewhere. Positions closer to the money carry more gamma, so the position changes character faster as the underlying moves, and the path matters more than the endpoint. The requirement per position is smaller, which is exactly the condition under which people write more positions and quietly rebuild the concentration they thought they had escaped. And on this snapshot the near strikes are where edge after costs is actually negative, at minus $40 at the 40 delta strike and minus $9 at the 30 delta, so "nearer the money" is a direction, not a destination. The peak in the table sits in the middle of the wing, not at either end of it.
When distant strikes make sense
Very distant strikes can be the right answer. They can be the right answer in combination with defined risk, disciplined position size, reserves adequate to the tail and genuine reinsurance sitting behind the book. Standing alone, sized by the comfort that a high win rate provides, they are the highest-win-rate route to ruin available in public markets. The arithmetic above is what distinguishes the two situations, and it is offered in place of a recommendation because which situation a given reader is in is not something a page can see.
The practical use of a table like this is not to pick a row. It is to force the comparison onto a common footing, so that skew, cost, capital and the true chance of a claim are all visible at once rather than one at a time. For more on how defined risk, sizing and reserves change what a distant strike means, see the companion discussion of book construction.
Key points
- A volatility threshold decides whether to write, not where on the strike ladder to write.
- Skew makes implied volatility rise all the way to the far wing, but edge after costs peaks in the middle of the wing and falls beyond it.
- Credit per dollar of margin requirement fell from 41.0 per cent at the 40 delta strike to 3.6 per cent at the 3 delta strike on this illustrative surface, a factor of eleven.
- Delta understates the chance of finishing in the money, and the relative error is worst at the distant strikes people choose because the delta looked comfortable.
- Writing nearer the money trades a lower claim frequency for higher capital efficiency, and on this snapshot the nearest strikes still showed negative edge after costs.
- Distant strikes can work alongside defined risk, disciplined size, adequate reserves and real reinsurance, and are dangerous when sized by win rate alone.
Related questions
why is delta not the probability of an option finishing in the money
Delta is a hedge ratio, the sensitivity of an option's price to a move in the underlying, and it only approximates the chance of finishing in the money under assumptions that real markets violate. In practice it understates that chance, and it does so in the seller's disfavour. On one illustrative surface of 45 day XSP put spreads, the 16 delta strike finished in the money 20.6 per cent of the time rather than 16 per cent, with the relative error largest at the most distant strikes.
does volatility skew mean far out of the money options are always better to sell
No. Skew does mean the implied volatility attached to distant strikes is higher, and on one illustrative 45 day XSP surface it rose from 16.3 per cent at the 40 delta strike to 20.9 per cent at the 3 delta strike. But higher implied volatility per unit of distance is not the same as more money left after trading friction and a loading for tail risk. On that same surface, edge after costs peaked in the middle of the wing rather than at the far end of it.
what does credit per unit of requirement measure
It measures how much premium a position collects for every dollar of margin it ties up, so it is a capital efficiency measure rather than a probability measure. On an illustrative ladder of 45 day XSP put spreads with a 15 point wing, it ran from 41.0 per cent at the 40 delta strike down to 3.6 per cent at the 3 delta strike, a factor of eleven. That decline matters because collecting comparable premium far from the money requires committing far more capital to the same underlying event.
why does a high win rate not make a strategy safe
A win rate describes how often a position pays, not how much is lost when it does not. Distant strikes combine a low probability of a claim with a thin credit and a large capital commitment, so a single correlated move can erase a long sequence of wins. Sizing a book by the comfort a high win rate provides, rather than by the size of the loss it conceals, is the common route to ruin in options selling.
what is the correlated event risk in selling multiple strikes
Selling several strikes on the same underlying feels like diversification but is not, because the event that breaches one strike is usually the event that breaches all of them in the same hour. Committing eleven times the capital to reach a comparable credit at a distant strike means eleven times the exposure to that single event. Genuine diversification requires exposures that respond to different drivers, not the same driver at different distances.
does a volatility threshold tell you which strike to write
No. A threshold answers whether implied volatility is far enough above a forecast of realised volatility to justify writing at all, and it is a gate rather than a selector. Strike choice is a separate question decided by edge after costs, capital efficiency and the true probability of a claim, and on an illustrative surface those three can point to a different part of the ladder than the threshold calculation alone would suggest.