Is this investment opportunity problematic?
Your Spidey senses are good. A good friend would not put you in such a position. It's simple, to skirt some issue (we'll get to that in a second) you are being asked to lie. All for a 15% return on your $$$$. <<< How much is that?  You can easily lend him the money, and have a better paper trail. But the bank is not going to like that, and requires this money from friends or family to be a gift. I've heard mortgage guys at the bank say "It's just a formality, we need this paperwork to sell the loan to the investors." These bankers belong in jail, or at least fired and barred from the industry. They broke the economy in 2008, and should be stopped from doing it again.