...or massive ammounts of Yuan thrown via helicopter (less likely than your proposition but the World does not cease to out-do my cynicism)
...or lots of chinese just claiming bankruptcy on their thrice re-hypothecated factory/luxury condo while keeping their Bitcoin wallets and stashes of gold.
I will speculate that there's not that many chinese with substantial bitcoin amounts though. I would guess that volume in their exchanges is from the super low or inexistant fees. I speculate chinese prefer old fashioned gold and monkey stamps for storage of value and Bitcoin is for gambling.
Notice that this is necessarily a stereotype or some sort of average if you prefer over the huge numbers of chinese people. Wasn't China one of the first places where a factory was accepting Bitcoin for payment? (and it wasn't a mining chips factory)