Pin risk: uncertain stock exposure around expiration
Near-strike expiration can leave the seller uncertain about the resulting shares. Price both branches before the option stops trading.
By OptionsKing. Publisher and editorial methods.
What you will learn
By the end of this lesson, you should be able to:
- Explain contrary exercise near a strike.
- Price both possible share holdings.
- Recognize unmatched spread settlement.
The uncertainty is about delivery as well as dollars. A closing price just outside the strike does not rule out exercise instructions, especially if the stock moves afterward. Follow the covered-call example into the weekend, then compare it with a spread whose legs may settle differently.
Friday, 4:00 p.m.
UBER closes at $72.49. You are short the $72.50 call.
One cent out of the money. OCC / Options Industry Council, Options Exercise FAQ sets automatic exercise at $0.01 or more in the money, and $72.49 does not clear that bar, so the default outcome is that nothing happens. The contract dies and you keep 100 shares and $153.
Except the default is not the only outcome available.
Why a penny is not safety
Three things are still live after the bell.
The instruction window. OCC / Options Industry Council, Options Exercise FAQ keeps the exchange cutoff open until 4:30 p.m. Central. A holder can exercise an out-of-the-money option if they want to. It is a bad trade by a penny and a fine trade if they have another reason.
The after-hours tape. The stock keeps trading. UBER prints $72.68 at 4:40. Now exercising is worth eighteen cents a share to the holder, and the option they are exercising is officially out of the money. That is not a loophole. It is the whole reason the instruction window exists.
The other side is not one person. Open interest on that strike represents a lot of holders with different reasons, and you are exposed to any of them who acts.
The weekend
Nothing to do. You do not know whether you own 100 shares of UBER, and you will not know until the notice appears Saturday.
The thing that makes this genuinely uncomfortable is that you cannot hedge it. Sell 100 shares Friday afternoon to lock in the price, and if you get assigned you are now short 100 shares you have to buy back Monday. Buy protection and you pay for something you probably do not need. Every action taken against one branch is a naked position in the other.
Monday
UBER opens at $71.10.
| Branch | What you hold | Worth | Plus premium | Total |
|---|---|---|---|---|
| Assigned Friday | cash from a $72.50 sale | $7,250 | $153 | $7,403 |
| Not assigned | 100 shares at $71.10 | $7,110 | $153 | $7,263 |
$140, decided by one cent.
Now look at which branch is which. Every covered call seller spends expiration Friday hoping the stock stays under the strike so they keep the shares and write again next month. Here, getting what you wanted cost $140, because the shares you kept fell further over the weekend than the upside you had capped.
That is not an argument for wanting to be assigned. It is an argument that the outcome you prefer and the outcome that pays more are unrelated, and the emotional pull towards keeping the shares is not analysis.
It is worse if you are not covered
A same-expiry long wing may expire without exercise while the short leg is assigned. After the wing expires, it no longer limits a resulting stock position's market exposure. A spread's terminal diagram assumes the legs are handled consistently; settlement requires separate attention.
A covered call pins into two acceptable outcomes. Other positions pin into an unacceptable one.
A vertical spread can have its short leg assigned while the protective long leg expires unused. The resulting stock position no longer has that option protection. If the long leg remains alive, it still offers protection but must be managed; it does not automatically respond to assignment.
A naked short call pins into being short 100 shares of stock at Monday's open, at whatever price Monday decides.
Both of those are why "it expired out of the money, so I did nothing" is a habit that works for years and then does not.
The only real fix
Do not be there. If the stock is within pennies of your strike on Friday afternoon, close the contract and take the certainty.
Price the certainty honestly. Thursday afternoon that call was $0.39, so closing cost $39 plus commission, and it removed the whole question. Against a $140 swing that looks cheap. Against the $153 credit it is a quarter of the trade, paid to avoid an outcome that was equally likely to help you.
Reasonable people land in different places on that. What is not reasonable is arriving at 3:55 on Friday without having thought about it, which is what the checklist is for.
Check your understanding
Why can an expiring spread leave stock exposure larger than its payoff diagram suggests?
Show the explanation
The short leg can be assigned while the long wing expires unexercised. The resulting shares remain after the option protection is gone. Check both legs and broker procedures rather than assuming automatic net settlement.
Common questions
What is pin risk?
The uncertainty a seller carries when the underlying finishes at or extremely near the strike at expiration. You cannot tell whether you will be assigned until the notices go out, so you do not know what position you hold until after the market has closed.
Can I be assigned if my option closes out of the money?
Yes. Automatic exercise only covers contracts a penny or more in the money, but a holder can still submit an exercise instruction until the exchange cutoff, and after-hours trading gives them a reason to.
Should I close a short option that is sitting on the strike?
Often, yes. On the worked example closing on Thursday cost $39 against a $140 swing between the two possible Monday outcomes. It is insurance with a real price, so decide before Friday afternoon rather than during it.
Is pin risk worse for spreads than for covered calls?
A spread's short leg can be assigned while the protective long leg expires unused, leaving stock exposure. If the long leg still exists, it provides option protection but requires management. Neither outcome should be assumed away.
Sources
Rules and thresholds above were checked against these documents on August 4, 2026. Exchange and broker rules change. Confirm anything you are about to act on with your own broker.
Keep reading
Do the math on your own trade
Every price in this article is an illustrative worked example, not a quote. Read Assignment and expiration for the rest of the series, and the disclaimer before you act on any of it. Selling options carries real risk of loss, and the loss can be far larger than the premium you collected.