A fast rise will undoubtedly lead to a correction eventually, that is clear. It would defy all market behaviour in history if it didn't. However, the 2011 situation was different. First of all, the rise was pretty much all hype based on the idea of this new cryptocurrency. There was no economy to speak of, except Silk Road that had just started. There were literally only a few Bitcoin companies in the whole world, and merchants such as Alpaca Socks accepting bitcoins. Then the hype went down, and security problems ran rampant within the community, leading to a total crash.
We might be seeing a correction, but that is different from a total crash. Totally different. The Bitcoin economy today is 10 times more mature than it was during the 2011 hype. We have dozens of Bitcoin startups all over the world. Silk Road is huge compared to what it used to be. Bitcoin is becoming widely accepted online, for pretty much any service one can imagine. We have VC's and Hedge Funds starting to invest in bitcoins and Bitcoin companies. Security of Bitcoin exchanges, while not perfect, is at a very high level compared to the past.
Fear of a larger crash is, at this moment, entirely unfounded. It's the definition of FUD. A large majority of market players do know this, and they're simply figuring out how deep the correction will be. The backbone of the economy becomes stronger every day, leading to a higher bottom price. This doesn't mean we don't have significant corrections, the market can still go to an overdrive. There is always the point where it's too much, regardless of where we're at, but my personal opinion is that with what is going on in the economy, any price below $50 is not a bad entry point for buyers, unless they're thinking super short term.
Now this one
Hedge Fund or whatever they are (making bitcoin accessible to more traditional investors) bought themselves some coins (using 2.5 million USD). I don't know when they started the acquisition, but it makes sense it was in January, no?
Now theses dudes also offer to short bitcoin. What keeps a smart contrarian investor to use them to short the shit out of bitcoin at some point?
Ok, speculation-time:
What percentage of the rally was due to them, how many coins do they have and how hard would shit hit the fan should a customer of them borrow the coins and sell them?