You should set your max win per bet according to your bankroll, such as 0.5% or 1% of your total bankroll. If you can't pay the loss, you shouldn't allow players to make such a bet in the first place.
This^^^
If you're going to start a gambling business, you NEED to be able to pay people who win.
If you can't pay a winner who bet over a certain amount, then you shouldn't allow the bet to be placed in the first place.
Anything else is just a boring old Ponzi. And those aren't any fun.
Lol