1. Exercise: When the option expires, the price of the underlying asset is greater than or equal to the exercise price of the option. Investors can choose to exercise, buy the underlying asset at the exercise price, and sell it, thus gaining income.
2. Waiver: When the option expires, the price of the underlying asset is lower than the exercise price of the option, and investors can choose to give up the option to avoid losses.
3. Extension: The option does not reach the target price, but investors think that the price of the underlying asset will reach the target price in the future, so they can consider extending the validity period of the option to get more time to wait for the price to rise.