Anyway, the question that keeps me from investing a dime into bitcoin is "What if it doesn't rebound?". If it really is being used as an investment vehicle and not a currency, than the answer to that, in my opinion, is eventually it will drop and continue to drop to the point where it's worth pennies on that dollar. With the boom and bust nature, I suspect many people will eventually just give up on it as a currency which would be close to a death sentence for bitcoin.
I am heavily biased towards index funds with the lowest fees so I'm rather pessimistic about bitcoin in general, just like I am about playing the stock market. It would be interesting to see what would happen if banks started to care about bitcoin. The market needs to grow many times over but I would expect them to be the only people making consistent money (and not even sometimes) just like they do on the stock market.