I can see myself recommending business that describes itself by mentioning OnlyFans to my friends, I can't see myself recommending the business to my family or coworkers.
I can totally see that.. I'll play around with some other naming options
It makes it seem like your product might be related to porn, like describing something as "PornHub for X"
I personally don't think there is anything wrong with "Onlyfans for stock trading", but I think "Patreon for stock trading" is a more general-public-palpable option, and fits just as well.
Notice how even the people suggesting the name is inappropriate aren't actually offended by it.