<prompt> Human: Point me in the right direction if theres a better sub for this question. I have a chef-friend who wants to start his own restaurant. He wants to raise 150,000 by issuing promissory notes to friends family. Hell have a lawyer draw these up; these arent IOUs on napkins. Hes proposing 6.537; return after 18 months. So you give him 10,000 and hell give you back your principal interest after 18 months. The failure rate of new restaurants is very high. There is a good chance Ill lose my entire investment. My argument to him is that the 6.537; is way too low considering I can go to Citibank and get a 2.7537; 2-year CD with zero risk. How does one determine what would be an expected return for any investment in a friends startup? Ive not found any resources online comparable to this particular investment.  <response>: great way to end a friendship here 