Just days ago there was a little over 60,000 BTCs on the sell side. Total. Now there are ~200,000 BTCs to $15. It would take almost 2.5 million dollars to get back to where we just were days ago, assuming a single giant buy. AND, the number of bitcoins that has suddenly appeared on MtGox doesn't represent the additional hundreds of thousands that will be entering the market throughout the week, assuming pirate actually makes good on his claim to cover everyone's deposits. In a odd twist of fate, it'd be better for the market for pirate to just run off with all those bitcoins. To say that supply has increased a lot is a laughable understatement, even now, and considering what's coming this looks worse than it did in the lead up to the crash to $2.
Bitcoin buyers are easy to understand. They want to buy as cheap as possible, or need the coins ASAP.
In sharp contrast Bitcoin sellers are really hard to understand. The same people that didn't want to sell at almost twice the price one day ago, want to sell everything at half the price as fast as possible.
So in other word it works like this:
buyer "hey, want to sell me at $14?"
seller "no way!"
buyer "ok, want to sell me at $8?"
seller "sure, take all I have"
Sellers always flood the market with cheap coins as soon as the price goes down. Because they now get less per coin? Are sellers actually stupid, or what does cause this?