If a person asks you to finance their gambling activities as a loan that they will repay after a certain period of time, that's still understandable because you will at least know that you will get your money back even if the gambler loses it all, but if it's like a partnership thing where the profits will be split, then it's obviously foolish to do it since gambling is all about luck and no one can earn guaranteed profits from it because it's a business for the owners and not for the players.
When a gambler ask to finance their gambling activities its like a partnership if you agree, and you will suffer more if he loss. Unless he said specifically that it's a loan and he will pay for it.
But regardless, i won't do on such things, you will only encourage him to gamble more, where in fact he already ask loan to gamble, that shit is already awful, and addiction that should be stopped early.
In my opinion, it is better to avoid requests like this, meaning that if there is one person, whoever it is, who asks you to finance his gambling with guarantees, just sweet promises, then don't follow his wishes, because obviously in gambling there is nothing promising and no matter how often you are involved in gambling, there is still no guarantee for you to win, everything will run randomly. Therefore you must really know about what gambling is, there is no income there especially consistently, do not act stupid by agreeing to the wishes of the person for fear that they experience defeat and finally they do not replace your lost money. That's right, unless from the beginning they said that they borrowed then one day you can collect it if the final result loses.
In my opinion only fools would finance gamblers, how can they believe or believe that partnering with gamblers will pay off, obviously the final result depends on luck, this is not a business or any activity that can provide good returns, but this is nothing more than an entertainment activity, so you better consider it than you lose.