Re: "HCP's (at least) one month long experiment of the Arakne Trading Bot"™
If the bot person would refund 30% on losses - that would be a decent incentive. Otherwise he doesn't risk anything. And he certainly doesn't care about customer relations, so you can't say the incentive would be retention or anything like that.
I am interested in your thoughts
In fact, bot creators will never refund you if the investor loses money, it's a safe way to work, just make sure he is always profitable and doesn't lose any money. But if he can refund 30% of the loss, he must be more responsible and his bot must be more efficient. It helps ensure the quality of bot, this case is mutually beneficial, on the other hands, it also helps him to compete easily with others to provide trading bots. Just an interesting idea that I think OP should consider to apply in your service.