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?
this is true, if you try to google about BTCJAM many investors are not happy with them coz most have defaulted the loans and they can't get back any money