Im not sure what this guys game is. What does he have to gain from bringing the market down?
The coins are going into the hands of long term inverstors for the most part and he is selling all his coins for cheap. Am i missing something?
It could be a miner from early on who mined a TON, convinced people to pay ridiculous prices before it was listed on an exchange, maybe got a bunch of real life associates to spend a ton of money to invest, got caught with his pants down, proceeded to vent about anything and everything because he'd found himself in a pickle, maybe started a pool then quit and now is back to try and salvage anything he can to get out of the hole that he buried himself in months ago...
But that's just a story made up by a fanciful observer like myself...

I spend far too much time traipsing through the Blockchain, it's easy to get lost in there and deduce things that aren't necessarily true. But I have to entertain myself somehow.
