The reason is that you can now buy BTC with RMB from banks (supposedly not possible since 2013).
If you understand the issues of "capital control" it is not hard to see why this would push the value of BTC up.
(the real question is how long until they "ban purchasing" again)
Spot on.
Chinese citizens are using mining and bitcoin as a way to move money out of China.
Exactly this. Well we will see how long it lasts as they ease off.
i also think because there are fake volume and everything is manipulated in their exchange, to encourage maybe foreigners to use their exchange more
since there are still restriction for chinese there, for taking out money