Financial Glossary
Exercise
Using your right: how option holders exercise to buy or sell the underlying asset.
What is Exercise?
Exercise is when an option holder uses their right to buy (call) or sell (put) the underlying asset. Exercising a call means buying 100 shares at the strike price. Exercising a put means selling 100 shares at the strike price. Exercise is optional—you never have to exercise. If the option is out-of-the-money at expiration, you simply let it expire worthless and lose only the premium paid.
American-style options (US equity options) can be exercised anytime before or at expiration. European-style options can only be exercised at expiration. Most traders don't exercise; instead, they buy or sell the option contract itself in the secondary market. But exercising is always available for deep in-the-money options when you want the underlying asset or want to lock in a price.
When to Exercise
You rarely want to exercise a call early because you lose remaining time value. A $2 call bought at $1 that's now worth $3 (having moved in-the-money) should be sold, not exercised—you'd recover $3 by selling, but only intrinsic value by exercising. Exception: if the underlying is about to pay a dividend, early exercise might make sense (dividends reduce call value post-ex-date).
For puts, early exercise can make sense before dividend dates. But generally, selling the option for remaining time value is better than exercising. At expiration, in-the-money options are automatically exercised by most brokers (or you must close or exercise manually to avoid this).
Disclaimer: Exercising options exercises forfeits remaining time value, which is usually not optimal. Automatic exercise at expiration can trigger forced stock positions. Before exercising options, consult a qualified financial advisor. Options involve substantial risk.