I am at the beginning of learning about options. I am reading a book on the subject. I am in a chapter about selling covered calls. The book says:
Defensive covered call writers may prefer the in-the-money strike price because it provides more premium up front. On the other hand, the stock will be called away if it's still in the money at expiration.
My (limited, newbie) understanding is that one can exercise the option at any time before the expiration. So that, in the case the book references, the call buyer might prefer to exercise the option as soon as it's in the money, and not wait until expiration (when it might be out of the money).
What am I missing?