China is the biggest bitcoin mining in the world for right now, and the largest factors to infect about the price is China. If the exchanger market from China down, the price is also down. So I believe that China can controlling bitcoin price and stock.
Yes true, china strongly influenced the bitcoin. When the Chinese new year, many of user sell bitcoin so the price drop from $1.160 to $800. And after the new year, they bought bitcoin again so the prices look stable and continues to rise.
There are more plausible explanations in regard to the price changes you refer to
And the causes of these changes are well known, and they have nothing to do with the Chinese new year since they are mostly related to the initiatives carried out by the Chinese authorities. The Chinese New Year happened in mid-February while the the price crashes you refer to had happened in January. In any case, it kinda looks that China is no longer controlling Bitcoin or its price. Bitcoin pretty much proved to be self-sufficient and global, i.e. not depending on any particular country (even if it is China) or whatever it might try to do to Bitcoin