I have lately seen adds for something called “peer to peer lending” which sounds like it would be a good thing to invest in, as there are minimal losses involved. However, the question is if there is an issue of ribis involved?
To cite a specific company the Lending Club www.lendingclub.com.
According to most authorities, there would be no prohibition in investing in such a company, provided that the owners of the company (or the majority shareholders) are not Jewish. For further details, see the article on the site entitled “Kosher Shareholding.”