Gox, or a company planning to takeover Gox, can right now buy 8 GoxBTC IOUs for 1 real BTC at BitcoinBuilder. This would be a legal way to give depositors a voluntary "haircut" outside of bankruptcy. Eyeballing the bitcoinity chart, it looks like they've done about 80,000 GoxBTC in trades. A lot of this was swing trading, but perhaps 20,000 GoxBTC have been bought for an average price of 0.25, or 5,000 BTC.
Of course we can't know, but if this was a coordinate effort to buy up the IOUs for cheap, then this action could have reduced Gox's BTC liabilities by about 15,000 BTC.
If the 750,000 BTC loss is FUD, this might make sense...
Would make a lot of sense.
The moment they released the statement about transaction malleability, I knew they were manipulating markets massively.