presumably because Gox has temporarily halted BTC withdrawals, a whole bunch of paranoids are selling their coins so they can withdraw the fiat instead. A panic sell off of BTC = massive price drop on Gox. I don't think there's anything more sinister than that going on - unless you can prove it?
Q) Weren't you the fkn clown who was telling everyone that Gox was just fine and that people shouldn't panic back when Gox was trading in high $500s?
A) Yes, you were! Don't say you weren't because your post history says that you were.
I say Karpeles is using an unlimited supply of Goxcoin which of course passes seamlessly for Bitcoin (on the MTGox exchange at least), in order to manipulate the price down as he takes real ledger authenticated Bitcoin off the table. Unbelievably, new money is piling into Gox and buying up Goxcoin thus pushing up the price.....all the better for Karpeles!
After MtGox goes under and Karpeles 'proves' that it did so as a result of cyber-theft from external parties, I say Karpeles will flee Japan and buy up a Vietnamese orphanage next to a doughnut factory, where he will happily live out the rest of his wretched creepy existence.
I think it's Satoshi.
He's had enough of Gox tarnishing the reputation of Bitcoin and he's going to grind it into the dirt.
"Oh save us, mightiest of Bitcoin whales!"
Another possible option is somebody had a huge bet based on the goxbtc price at some derivative market & gained more from shorting than they lost tanking the price.
Shrewd thinking. But who would be dumb enough to take the opposite end of such a contract when such an unfavourable outcome could be so easily manipulated by the right/wrong sort of people?