Options Exercise, Assignment and Settlement

The whole unit on one sheet: what exercising an option actually produces, how assignment gets picked, and how margin obligations flip once exercise happens.

What Does Exercising an Option on a Future Actually Produce?

• Exercise is the holder's act of invoking the contract, converting the option into a futures position at the strike, not the physical commodity and not a lump-sum cash payout.
• A call exercised gives the holder a long futures position and the assigned writer a short one. A put exercised gives the holder a short position and the assigned writer a long one.
• Any in-the-money worth is realized the ordinary futures way: through variation margin on the new position, not as cash paid at the moment of exercise.

How Does Assignment Get Picked?

• Assignment is the clearinghouse's designation of a writer who must take the opposite futures position. Neither the buyer nor the writer chooses who is assigned.
• Most contracts use random assignment; some product families (including many energy and metals contracts) use a deterministic pro rata method instead. Either way, a writer cannot dodge assignment.

How Does Margin Change the Moment an Option Is Exercised?

• Before exercise: the buyer posts no margin (the premium paid is the maximum loss); the writer must post performance-bond margin, because the writer's risk is open-ended.
• After exercise and assignment: both sides hold futures positions and both must post futures margin, subject to daily variation margin. A former buyer who owed nothing now holds a margined futures position.

When Can an Option Be Traded or Exercised?

• The last trading day (the last day to offset the option) and the expiration (exercise) date (the last day to exercise it) are distinct dates; the last trading day can fall on or before expiration.
• American-style options are exercisable any time up to expiration; European-style options only at expiration. Series 3 tests both, so match the style to the named product.
• Left alone at expiration, an in-the-money option is typically auto-exercised into a futures position; an out-of-the-money option expires worthless. Some contracts allow contrary instructions to override the default.

Which Gotchas Trip Students Up?

• Exercise produces a futures position, not the commodity or a cash payout. A choice saying exercise "delivers the commodity" or "pays intrinsic value in cash" skips the futures position that actually results.
• Assignment is not always random. Random is common, but some product families use pro rata; either way, neither party picks the counterparty.
• A former buyer's margin obligation changes the instant they exercise, from zero to a margined futures position.
• The last trading day and the expiration date are not automatically the same day, and offsetting stops being available once the last trading day passes.

Memory Aid: American = Anytime; European = only at the End.

One-Breath Recap

Exercising an option on a future converts it into a futures position at the strike, not the physical commodity or a cash payout, giving a call holder a long position and the assigned writer a short one, and a put holder a short position and the assigned writer a long one; assignment is picked by the clearinghouse, usually at random though some product families use a pro rata method, and neither party chooses it; before exercise the buyer posts no margin while the writer posts performance-bond margin, but after exercise and assignment both sides post futures margin subject to daily variation margin; American-style options exercise anytime up to expiration while European-style options exercise only at expiration, with an in-the-money option typically auto-exercised and an out-of-the-money one expiring worthless.

Need more than the recap? Read the full Options Exercise, Assignment, and Settlement unit.