Why the currency falls...?

Why does the crypto currency fall?
I think that this is more connected with the law that led in China about the closure of the Manga and in that country and the stock exchange.
Statistics on the world where bitcoin is "extracted", in China is located from 75 to 85 percent
Chinese move their farms to another country and then the rate to grow to the former level or even higher.
The third reason is that it banned the South Korea ban on the exchange of crypto currency(>).