I wish there was. The only decent investment that I have found is Bitfinex (lending BTC/USD there), and I'm not even sure about that one.
How can we expect BTC ecosystem to develop then. If there s nothing we can actually invest in??
Buy bitcoin and hold them?
Well, just trolling, honestly:
I think that some of those dice sites are a good choice, just-dice has this investment option.
Just-dice has been in the game for long enough time to be called "trusted".
But there is always a chance that the site is hacked or the owners (or some of the programmers) take all the coins and run.
In real life there are also risk, there are many who was scammed on stocks, buying a promissing stock that was just a pump'n'dump with no real potential,
that happen all the time. Saw a documentary about it.
I think the key is to invest in many different things so you can take a hit or two and still be ahead.