Rpietila - I've wondered about what you just brought up. I guess there are still quite a few people that want to unload, even though they are bulls, they take the occasional profits and if you have 10's of thousands of BTC, unloading some on a down move (to buy back later) might not be bad. But what a bounce that will be...
I think Bitcoin is expanding in waves, each one is an order of magnitude bigger. In the end there may be the final forward escape, the singularity event, if everyone decides to leave fiat currency in one supermove consummating in 6-9 months. Until that happens, it just takes 12-24 months to reach a new wave ("bubble") high, driven by the investors that heard about Bitcoin during the previous top.
Now we are waiting for millions of people who heard this year, to summon their money to buy. On the other side, there is almost no one who still has coins to sell. The upmove 2 weeks ago showed that price can go up 50% with almost no buying pressure. There are so little bitcoins available that there will be an immediate squeeze as soon as the current bears decide to buy back. I bet almost nobody did 2 weeks ago. With all likelihood, most of them will never recoup their coins. This, naturally, has to be so - otherwise "there would not be enough coins for all", and price would rise even more. In the end, nobody will sell bitcoin for fiat, but it seems we are not there yet. (And may not be, if things change: I have been waiting since 2006 that nobody would sell gold and silver for fiat, still they are obtainable although silver is tricky).