Quick Answer
Exercise is the option holder's act of invoking the contract, converting the option into a futures position at the strike. Assignment is the clearinghouse's matching designation of a writer who must take the opposite futures position. The holder controls exercise; the writer cannot choose or avoid assignment.
These are options on futures contracts, so the whole process turns on one fact: exercising an option produces a futures position, not the physical commodity and not a cash payout. Start with who does what.
Exercise and Assignment
Every exercised option has two sides: the holder who invokes the right, and the writer who is handed the matching obligation.
- Exercise: the act by which the option buyer (holder) invokes the right in the contract, converting the option into a futures position at the strike. A call becomes a long futures position; a put becomes a short one. The exercise price is just another name for the strike price.
- Assignment: the clearinghouse's designation of an option writer (grantor) who must take the matching opposite futures position when a holder exercises. Assignment is the writer-side event that mirrors the buyer's exercise.
- Exercise is a holder decision; assignment is imposed on a writer by the clearinghouse. The writer does not choose to be assigned, and the buyer does not choose which writer is assigned.
Think of it this way: picture a coat check. The holder hands in the ticket (exercises), and the attendant, not the holder, decides which specific coat on the rack gets pulled to satisfy it. The writer is whoever happens to own that coat, and they cannot wave the attendant off.
How the Clearinghouse Assigns
When a holder exercises, the obligation has to land on some writer of the same series, and the clearinghouse is the one that picks.
- The clearinghouse assigns the obligation to a writer of the same series, chosen by neither the buyer nor the writer.
- Two allocation methods are used across different products: random assignment (an approved algorithm, used for most contracts) and a deterministic pro rata method (used for some product families, including many energy and metals contracts), which allocates proportionally rather than by lottery.
- The assigned writer is then obligated to take the opposite futures position at the strike. Notice of assignment reaches the writer through their clearing firm.
- Under either method, a writer who is short the option cannot choose to avoid assignment or predict it with certainty.
Memory Aid: The bUyer invokes the right (exercise is Up to the holder); the writer is Assigned (Assignment is done At the writer, by the clearinghouse). Buyer acts, writer gets acted upon.
Exam Tip: Gotchas
- Assignment is made by the clearinghouse, never chosen by the buyer or the writer. Most contracts use random assignment, but some (including many energy and metals contracts) use a deterministic pro rata method instead. Either way, the exercising buyer does not pick which writer gets assigned, and a writer cannot choose to avoid assignment. Treat "the writer chose to be assigned" or "the buyer selected the counterparty" as wrong regardless of which method applies.
- Do not assume assignment is always random. The buyer-never-picks and writer-cannot-dodge points hold under both the random and pro rata methods, so an answer that says assignment is "always by lottery" is overstating it.
Call Exercise Outcome
A call is the right to go long, so exercising one puts the holder into a long futures position.
- Exercising a call gives the holder a long futures position at the strike price.
- The assigned writer of that call receives a short futures position at the strike price.
- Both sides now hold real futures at the strike: the holder long, the writer short, on opposite sides of the same price.
Put Exercise Outcome
A put is the right to go short, so it mirrors the call.
- Exercising a put gives the holder a short futures position at the strike price.
- The assigned writer of that put receives a long futures position at the strike price.
- Again both sides hold opposite futures at the strike: the holder short, the writer long.
Call vs Put Exercise Outcomes
Lining up both option types side by side makes the mirror easy to check under exam pressure.
| Option exercised | Holder's resulting futures position | Assigned writer's resulting futures position |
|---|---|---|
| Call | Long futures at the strike | Short futures at the strike |
| Put | Short futures at the strike | Long futures at the strike |
Memory Aid: Call the elevator to go up (holder goes long); put the trash down (holder goes short). The assigned writer always takes the opposite side.
Exam Tip: Gotchas
- The call and put outcomes are mirror images, and the writer always sits on the opposite side. Exercising a call makes the holder long and the writer short; exercising a put makes the holder short and the writer long. Catch yourself giving the holder and the writer the same direction and you have it wrong.
What Exercise Produces
Exercise settles into futures, and any in-the-money worth shows up the ordinary futures way.
- Exercise produces a futures position marked to market from the strike, not the underlying physical commodity and not an automatic cash payment of intrinsic value. (In-the-money (ITM) means an option currently has exercise value.)
- Any in-the-money worth is realized the ordinary futures way: once the new position is marked to market from the strike, the difference between the strike and the current futures price shows up as variation margin (a gain to the favorable side, a loss to the other), not as a lump-sum cash settlement of the option at exercise.
- Physical delivery, if it ever happens, is a separate later event that belongs to the futures contract's own delivery process (covered in the unit on offsetting contracts and delivery), not to the act of exercising the option.
Exam Tip: Gotchas
- Exercising an option on a future produces a futures position, not the physical commodity and not a guaranteed cash payout of intrinsic value. A holder who exercises an in-the-money call is now long a futures contract at the strike. The profit is realized through mark-to-market variation margin on that futures position, not delivered as cash at the moment of exercise.
- Delivery is not part of exercising. If a choice says exercise "delivers the commodity" or "pays the option's intrinsic value in cash," it is skipping the futures position that actually results. Physical delivery, when it happens at all, is a separate step in the futures contract's own delivery process.