Again: The script never says they were "investors," but it is logical to assume they were.
I know, but I wrote that it is
implied by Roth's statement, and I stand by it. We do not necessarily need a confirmation in the film to know that Roth had other investors. I imagine Roth would only hand over control of his hotels to his business partners.
Sonny, have you ever been to Cuba?
No, but I would like to go there sometime. I suppose you have?