I just read another thread that a lot of shorts were opened on the US market today and immediately put two and two together but if what people are saying about him being unable to sell any more coins until after late September is true then who knows what's behind that.
Kobayashi could pull off a great trick by shorting bitcoin himself and then moving those funds to an exchange, he wouldn't even have to sell anything but he'd already have profited from that.
He sold sufficient amounts to meet the Mt Gox liaabilities as defined by the Japanese courts. He doesn't need to sell any more - I think under Japanese law, the rest of the coins belong to Karpeles.
