Opinion on fee to charge for theoretical 50%goa per month bot


This is a theoretical case. I am developing a system for a client, and my actual numbers and system are different than this example but I want your feedback on what you think a fair fee would be to charge if I had developed a trading bot that was doing an average of 50% gain/month at 30% max drawdown sometimes.

This bot would only be part of a trade copy service, and my inclination would be to charge a percent of the gain people made. So if someone copied the bot and made 50% on their account, the company would make x% of their profit as the fee. What fee would be the maximum you would pay monthly for a 50% goa/mo? Or if you think a flat fee would be better, what should it be?

Do you think 20% fee of the profit would be acceptable? 10%? Would 50% be too much? (even though if they made 50% gain, they'd still make 25% after the fee per month, still an insane amount.

Again these are theoretical numbers just to help me figure some things out, your input would help me determine what others think. I have no product or service I am selling, I am only gathering info. Thank you!
Hedge funds typically charge 15-25% of the annual gain. Charging 50% of your monthly gain with no clawback for the down months means you could theoretically end up keeping much more than 50% of the returns in a year.

As an investor I'd ask what percentage of months is your (hypothetical) system profitable, and what is the avge. monthly gain / avge monthly loss?