Exercise and Assignment
Exercise is when an option holder uses the right to buy (call) or sell (put) the underlying at the strike price. Assignment is the other side: the option seller is chosen to fulfil that obligation and must sell or buy the shares at the strike.
Most options are closed before expiry, but the contract is built around one moment: exercise. The buyer decides whether to use the right; the seller has no choice and gets assigned. Understanding both sides matters, because an unexpected assignment can leave you with shares — or a short position — you never planned to hold. This entry explains how exercise and assignment work, with worked examples.
- Category
- Derivatives
- Reading time
- 4 min
- Also called
- Option exercise, Option assignment, Early assignment
- Updated
Exercise and assignment in plain words
When a buyer uses the right to buy or sell the underlying security, that is called exercising.1
The option seller, or writer, accepts the obligation to buy or sell if the contract is assigned — meaning their broker requires them to meet the contract's terms.2
An assigned call seller must sell shares at the strike; an assigned put seller must buy shares at the strike.2
How exercise and assignment work, step by step
The holder decides
Usually only worth it if the option is in the money. See Option Greeks.
Exercise notice is sent
Through the holder's broker.
A seller is chosen
The clearing system assigns a writer of that option.
Shares change hands
At the strike price, regardless of the market price. See Strike Price.
Index options settle in cash
The difference is paid instead of shares.
Expiry rules apply
In-the-money options may be exercised automatically. See Expiration Date.
Worked examples
Example 1 — Exercising a call
+$700You hold one $70 call (100 shares) bought for $3. The stock is $80 at expiry and you exercise.
| Pay for shares | 100 × $70 = $7,000 |
| Shares worth | 100 × $80 = $8,000 |
| Profit after premium | $8,000 − $7,000 − $300 = $700 |
A call lets its buyer purchase the shares at the strike at any time before expiry.1
Example 2 — Assigned on a short put
−$400You sold a $50 put for $2. The stock falls to $44 and you are assigned.
| Must buy | 100 × $50 = $5,000 |
| Market value | 100 × $44 = $4,400 |
| Net after premium | −$600 + $200 = −$400 |
If a put is assigned, its seller must buy the underlying at the strike price.2
Example 3 — Assigned on a covered call
+$650, upside cappedYou own 100 shares bought at $40 and sold a $45 call for $1.50. The stock rises to $52 and you are assigned.
| Shares sold at strike | 100 × $45 = $4,500 |
| Gain on shares | $4,500 − $4,000 = $500 |
| Plus premium | $500 + $150 = $650 |
An assigned call seller must deliver shares at the strike, giving up the gain above it.2 See Covered Call.
Exercise vs assignment
| Aspect | Exercise | Assignment |
|---|---|---|
| Who | Option buyer (holder) | Option seller (writer) |
| Choice | A right | An obligation |
| Call | Buy at strike | Sell at strike |
| Put | Sell at strike | Buy at strike |
When exercise and assignment matter
Covered calls
Shares may be called away. See Covered Call.
Cash-secured puts
Assignment means buying the stock. See Cash-Secured Put.
Spreads near expiry
One leg can be assigned before the other. See Vertical Spread.
Dividends
Calls are more likely to be exercised early before an ex-dividend date. See Ex-Dividend, Record and Payment Dates.
Advantages and disadvantages
Advantages
- Gives holders the actual shares or cash value.
- Makes the option's value real at expiry.
- Standardised and handled by the clearing system.
Disadvantages
- Sellers can be assigned when they least expect it.
- Assignment can create large stock positions.
- Exercising early usually throws away time value.
Going deeper
Read as far as you need. Each level builds on the one before it.
Most options are closed, not exercised
Beginner
Selling an option before expiry usually captures more value than exercising, because exercise gives up any remaining time value. See Option Greeks.
Expiry timing
Intermediate
Standard monthly options generally expire on the Saturday after the third Friday, though weekly and other expirations exist.1 Check your broker's rules for automatic exercise.
Early assignment
Advanced
Options on individual US stocks can usually be exercised at any time before expiry, so a short option can be assigned early — most often when it is deep in the money or just before a dividend. A call buyer, for example, can buy the shares at the strike at any time before expiry.1 See American and European Options.
Common mistakes
Forgetting assignment risk
Short options can be assigned before expiry.
Lacking cash for assignment
An assigned put needs money to buy the shares.
Exercising too early
You lose remaining time value.
Ignoring automatic exercise
Slightly in-the-money options may be exercised at expiry.
Check your understanding
Test yourself before moving on. Each answer comes with an explanation.
Key points to remember
- Exercise is the holder using the option's right.
- Assignment is the writer being required to fulfil it.
- Assigned calls mean selling; assigned puts mean buying.
- US stock options can be assigned early.
- Selling an option often beats exercising it.
Frequently asked questions
Can I be assigned before expiration?
What happens if I don't have the cash?
Do I have to exercise an in-the-money option?
Further learning
- Options
Calls and puts explained.
- Covered Call
Where assignment is common.
- Option Greeks
Which options are worth exercising.
Sources
This article is written in our own words. The sources below support the specific facts, rules and figures marked with a number in the text. Links open the original publisher’s page.
- Investor.gov (SEC). An Introduction to Options – Investor Bulletin (opens in a new tab) Checked .
- FINRA. Options (opens in a new tab) Checked .
Educational content, not financial advice. Examples use hypothetical prices and simplified costs; actual fees, margin rules and regulations vary by broker, market and country. We are not affiliated with any publisher linked above. Last reviewed . Report an error or request a source credit.