Honestly this is the question we don't know for sure the answer, but we know that they are not selling off (going out of BTC) - it would be much more simple and much more profitable to sell it on OTC - even 50k+ coins. But much more believable is, that they want to accumulate cheap (maybe even through cheap OTC bulk buys) and rinse & repeat the bubble. Being end goal BTC at 0 is low probability, cause they were probably early in the game and understand the things well, this would be possible only in the case if someone is doing this who doesn't want BTC to succeed (banks, gvt...). Or if these coins are stolen and they really have xxx.000 BTC (but probably exchanges would get them). But all this killing BTC in imo less than 10% chance.
And remember - China is not the cause of all this rise and fall, its the tool.
My theory is that they want to push to 350, but not much lower. Lower towards $200s will encourage longer-term holders to sell, and of course the whales need them as support on the way up. Their dumps are getting smaller as the price gets lower. They were rejected @ 375 and will have to spend considerably more coin to knock the price down.
They don't dump anymore, they just dump in mostly their own walls and when price is high (paypal push). They control the sentiment and orderbooks and price action so others sell for them. Do you think they care if price is $100 for two days so they can get XX.000 BTC and they push it to 500 in the next two days. Its all about their plan. To bad we don't know what it is.