I think op is asking of gambling sites that offer investments like backrolling. Gambling is very risky but investments into gambling sites has reduced or less risky. I think sites like Bustadince offer investments platforms and you can visit the site for more information on how it works.
At first I didn't understand what was meant by the OP and my thoughts regarding what the OP was asking might mean what you said that the OP looked like a gambling site that had investment services. in my opinion, all gambling is also an investment but the benefits depend on our luck in playing.