The volatility in the bitcoin price just demonstrates how the majority of the people trading it have no conception of how to value the underlying asset (i.e. demand for a low cost transaction system) and thus it is speculators leading speculators a la the blind leading the blind.
The current sharp price decrease is because people are worried that whoever wins this auction (and the subsequent auction of DPR's coins) will want to exit that position. Thus their will be an oversupply in the market and cause the price to decrease. Expecting this, people are taking that into account and trying to get out before the oversupply, causing a self fulfilling prophecy based on bad underlying analysis.
Why would someone go long bitcoins (i.e. buy them and in such quantity) through such a difficult process as dealing with the US gov't to so quickly exit their position?
My hypothesis is that it will be either rich institutional investors, hedge funds, or similar large investors who see this as an opportunity to acquire bitcoins at an undermarket price.
I think many of those groups would sit on their position (and not sell them). Further, if they were to sell them, they would want to do so in a way that didn't dramatically affect the price (thus over many days, weeks, or months). Given that 30K bitcoins is far less than the total bought/sold on exchanges every day, it should be presumed that they can exit this position over a sufficient timeline in order to not cause negative pressure on the price (if the auction winners even want to sell -- which as I analyzed above, I don't think they would).