Fees paid on fidelity /RH trades

I'd like to do a recurring stock buy of $100 per week.
If I were to do 20 per day as opposed to 100 once a week, would I be paying for more doing it daily?

I know the trades don't cost anything on paper but there must be a way they make out, I've heard of a collar?

I like the idea of buying every day but I don't want to pay more in hidden fees either.