Most of us may be aware of this information that China is about or might have imposed trading charges per bitcoin transaction. ~
it was never a might, never a possibility, it was in fact a sure thing. as soon as PBOC started looking at them and ordered them to stop more than half of their services they had to make some chances and surely enough they added a 0.2% fee on each trade just like any other exchange out there.
and by the way it is not fee per bitcoin transaction it is fee per trade (or order).