Is China trying to control Bitcoin?
They are manipulating the bitcoins price but not controlling them, you might notice that every time that bitcoin price have reached $1000 or exceeds to $1000, they are dumping their coins to affect the bitcoins price since most of the bitcoin users are from their country that is why.
So, anytime right now, they will DUMP their bitcoins, and sell it, and when its price would be lower that the price when they sold their bitcoins, they will buy again and wait for the bitcoins price to go up high again and do this thing again and again and again.
That is true, that is one of the factors how china/chinese users almost controlling the bitcoin because they got the majority of the bitcoin and most of the big investors or let say amount of users are there in china. So it is very easy to them to manipulate or control the price of bitcoin since they have an advantage which is having the most of bitcoin. They always creates hypes which can lead for them to make profit even though they bought their bitcoins at a high price.