Expiration week generates more anxiety — and more unforced errors — than any other part of the options cycle. Most of it is avoidable: assignment and expiration follow mechanical, knowable rules. This page explains exactly what happens to long and short options at expiration, when early assignment occurs, and how the desk manages positions into the final week.
What expiration means
Equity options expire on the third Friday of each month (monthly expirations), with weekly expirations available on most liquid underlyings. The exact expiration time is 4:00 PM ET on expiration day for most equity options — the closing price at the bell determines everything. Index options (SPX, NDX) are European-style and cash-settled: no shares change hands, and they settle to a special opening quotation on expiration morning.
At expiration, every option is worth exactly its intrinsic value — no time premium remains. A call is worth max(0, stock price − strike); a put is worth max(0, strike − stock price). Anything out of the money is worth zero. This convergence of price to intrinsic value is what "time decay" has been driving toward all along.
Automatic exercise: the $0.01 rule
Here's the part that surprises people: you don't have to do anything for an in-the-money option to exercise. The Options Clearing Corporation (OCC) automatically exercises any long option that is in the money by $0.01 or more at expiration. This is called exercise by exception — it happens unless you explicitly instruct your broker otherwise.
Practical consequences:
- A long call that's $0.05 in the money at the bell becomes 100 shares of stock (long) at the strike price, settled the next business day. You need the capital or margin to support that position.
- A long put that's in the money becomes a short stock position at the strike.
- Out-of-the-money options simply vanish — no action, no cost.
If you hold a long option into expiration and it's even slightly in the money, expect to wake up with a stock position. Plan for it or close the option before the bell.
Early assignment: when shorts get called away
Short options can be assigned at any time before expiration — the option holder can exercise whenever they choose. In practice, early assignment is rare for most of an option's life and becomes a real consideration in specific situations:
- Short calls on a stock going ex-dividend. If the dividend exceeds the call's remaining time value, the call holder exercises early to capture the dividend. This is the single most common cause of early assignment.
- Deep in-the-money short options with almost no time value left — the holder has nothing to lose by exercising.
- Short puts are occasionally assigned early, but there's little incentive: the put holder would rather sell the put (capturing remaining time value) than exercise it.
When you're assigned on a short call, you're short 100 shares at the strike price. On a short put, you're long 100 shares at the strike. Assignment itself isn't a loss — it's a transaction at the strike price. The risk is waking up with an unintended stock position (and its margin requirements) over a weekend.
For defined-risk spreads, assignment on a short leg is manageable: the long leg covers the obligation. A bull call spread assigned on its short call can exercise its long call to flatten. The mechanics work — but the resulting stock positions, margin calls, and weekend risk are why the desk prefers to close spreads before expiration week rather than manage assignment logistics.
Pin risk: the Friday afternoon special
Pin risk is the edge case that deserves respect: the underlying closes exactly at or within pennies of a strike at expiration. Your short strike might be $0.01 in the money (auto-exercised against you) or $0.01 out (expires worthless) — and you won't know which until Monday morning's assignment notices.
If you're short the 100 strike and the stock closes at $100.00, you may be assigned 100 shares short... or not. The uncertainty itself is the risk: you can't plan a position you might or might not have. The only clean solution is to not hold short strikes into the closing bell when the underlying is pinned near them.
Managing into the final week
The desk's expiration-week protocol:
- Close or roll by Wednesday of expiration week for most structures. The remaining premium is rarely worth the gamma risk, assignment logistics, and pin risk.
- Never hold short strikes through the closing bell when the underlying is within a few cents of the strike. Close the spread; the pennies of premium aren't worth the weekend uncertainty.
- Check ex-dividend dates on any underlying where you're short calls. If a dividend exceeds the call's time value, expect assignment and manage ahead of it.
- Know your broker's cutoff times for contrary exercise instructions (telling the OCC not to auto-exercise, or to exercise an option that's technically out of the money). These deadlines are typically Friday afternoon — know yours before you need it.
- Index options simplify everything. European-style, cash-settled index options (SPX) can't be early-assigned, which removes the entire assignment dimension. This is one reason the desk prefers index underlyings for short-premium structures.
The bottom line
Nothing about expiration is mysterious once you know the rules: $0.01 in the money means automatic exercise, short options can be assigned anytime (usually around dividends), and pin risk is solved by not being there. The traders who get hurt at expiration aren't unlucky — they're unprepared. Close early, respect the dividend calendar, and never let a few cents of remaining premium talk you into weekend assignment risk.