Why are you not making 10x your profit ?

You have a profitable strategy. It is consistent, and repeatable. You have been in green for a long while.
Let's assume you can significantly increase your size without invalidating your strategy, why are you not doing it ?
Why are you not sizing up to make significantly more money?
What is preventing you ?

Edit: Guys, I don't mean go 10x in one shot. Let me explain what I mean. I have read around here multiple times, people who are consistently profitable, pulling out a certain amount of money every day but capping themselves at a certain amount of contracts.
I was wondering why they don't they go to the next level if their account and strategy allow it ?