Seems to me there is developing a consensus in the market that 1BTC is AT LEAST worth something like $550. All the new people coming in have in the back of their heads that price has been +$1000 and with the momentum and press Bitcoin has now, it is just common sense that this is a good price. Which can be seen in buying pressure whenever we move down below 600. IMHO.
if you knew about bitcoin when it was 1000 than sure 550-600 is really cheap, if you knew about bitcoin when it was $10 and if you were present on the crashes we had than 500-650 still looks optimistic, although I have to point out that any move you do now is really risky because bitcoin by nature is unpredictable.
I know that I risk so much but I make sure that I wont regret my action if the price will start climbing so fast.... most of the time I am all BTC but when I have the sense of the price going down I sell 50% and open limit orders and wait, if the price start climbing back my strategy is to cash out.
since I invested in bitcoin, I cashed out less than 15% of my holdings, I always think about cashing out some of my profits but I always buy back because at the moment I don't really need that cash...
When comparing how the price looks for a person knowing bitcoin when it was at $10 with a person getting to know it the last months, you have to take into account how enormous Bitcoins progress towards adaption has been. At $10 it was basically just a bet for the pure visionaries, totally unproven in all aspects but the theoretical. At $1000 we were dealing with something that just might change the concept of money as we know it. Since then the price has halved, and apart from the China spectacle, the good news keep rolling in.
Personally I am fully accepting towards the prospect of losing my entire Bitcoin investment, but I will not risk the regret of not acting on and taking the chance on something that resonates completely with me. I have a strong feeling Bitcoin will change the world. If it doesn't, I will go on with a smile on my face, feeling good that i did what i believed to be right.