Assignment
Assignment is when an option seller is called on to fulfill their obligation after a buyer exercises. Learn what triggers it, how it feels, and how to manage it.
Assignment is when the seller of an option is called on to fulfill their obligation, because a buyer somewhere has exercised. It is the flip side of exercise: the buyer uses their right, and a seller is assigned to complete the deal.
Assignment is the risk every option seller lives with. Understanding it turns a scary word into a manageable event. Let me show you how it lands.
The Coupon Comes Due
When you sell an option, you are the store that issued a coupon. As long as no one redeems it, you simply keep the premium. But if a holder exercises, you are assigned: you must honor the coupon and deliver on your promise.
Assigned on a call you sold, you must deliver 100 shares at the strike. If you own them (a covered call), you hand them over. If you do not (a naked call), you must buy shares at the market to deliver at the strike, a painful loss if the stock has run up. Assigned on a put you sold, you must buy 100 shares at the strike, even if the market price is now lower.
How and When It Happens
Assignment can feel random, and in one sense it is. Knowing the pattern keeps it from catching you off guard.
It is triggered by exercise. You are only assigned when a buyer of a matching option exercises. That is most likely when your short option is in the money, since a holder gains by exercising then.
Allocation is random. When holders exercise, the clearinghouse assigns those exercises to sellers at random. Being short an in-the-money option means you could be assigned; whether you are, on any given day, is the luck of the draw.
Mostly at expiration, sometimes early. In-the-money short options are usually assigned at expiration. But American-style options can bring early exercise, most commonly on short calls just before a dividend, or when a stock closes right at your strike and leaves you guessing, which is pin risk.
Managing Assignment Risk
Assignment is not something to fear so much as to plan around, and sellers have clear tools.
Close before expiration. Buying to close a short option that is near or in the money removes the obligation entirely. No open short, no assignment.
Roll the position. Moving a threatened short option out in time, or to a different strike, can sidestep an imminent assignment while keeping the trade alive.
Be ready to accept it. Sometimes assignment is fine, even planned. A covered call getting assigned simply sells your shares at the strike you chose; a cash-secured put getting assigned buys shares you wanted anyway. The trouble comes only when you are assigned on an uncovered position or one you cannot afford, which is why naked selling demands caution and adequate margin.
- Assignment is the seller fulfilling their obligation after a buyer exercises.
- Short calls deliver shares; short puts buy shares, at the strike.
- It is most likely when your short option is in the money, and allocated at random.
- Manage it by closing, rolling, or being ready to accept the shares.
Pop Quiz
Three quick questions to see what stuck. Pick an answer and the explanation shows up right away.
Who gets assigned?
Assignment lands on the seller, who must fulfill the obligation when a buyer exercises.
When are you most likely to be assigned?
Holders gain by exercising in-the-money options, so in-the-money short options are the ones assigned.
How can a seller remove assignment risk on a short option?
Buying to close ends the short position, so there is nothing left to be assigned on.
Bottom Line
Assignment is the seller's coupon coming due: a buyer exercised, and now you must deliver shares on a short call or buy them on a short put, at the strike. It is triggered by in-the-money exercise and allocated at random, mostly at expiration but sometimes early.
It is a manageable event, not a disaster. Close or roll a threatened short option, or be ready to accept the shares when assignment is part of the plan, as with covered calls and cash-secured puts. The real danger is only being assigned on an uncovered position you cannot cover.
Keep going: the buyer's side of the same event is exercise, the combined view is exercise and assignment, and the early kind clusters around dividend risk.