Of course we can, no secret again if china is the largest owner of the bitcoin, many forums which states they unite for get the benefit of the price of the bitcoin.
Well it's worrying but it's possible China can manipulate the prices single handed due to their stake in the Bitcoin mining network and the amount of Bitcoin owners and bitcoins in their possession. The prices are generally regulated by demand and supply and since they have more in their possession they can either creat a demand (by refusing to sell) or create an abundance of supply.