Google havelock investments. They sell shares to many bitcoin companies. BTCjam also offers a place like that, where you can make a nice 20% annually.
I have heard bad things about BTCjam, it is populated by scammers. They take out small loans, repay them to get good ratings, then take out a big loan and walk away. Rinse and repeat under a new username. So the site reports something like 75% repayment rate (I don't know the current stat), but the 25% that are not paid back are much larger loans than the ones that do get paid back. Basically, from an investor's point of view, it is a good way to lose money.
Have you had a look at
mpex.ws as a place to invest?