It's a manipulated market!
It is estimated that 40% of bitcoins are held by less than 1,000 people who are able to communicate with each other. This is reminiscent of the manipulation of the price of diamonds by De Boers warehouses. In early December 2017, while bitcoin was free falling in minutes from $ 13,000 to $ 9,000, while CoinBase the main stock exchange of Bitcoins closed to trade, a single massive purchase order sent the Bitcoin over the $ 11,000.
For me, this is clearly the sign of a manipulated market. This is reminiscent of raw materials in the 19th century in the USA where "corners" were organized by "unions". All supervisory authorities issued warnings. All financial institutions have warned against investing in Bitcoin. In the same vein, you can find purchases / sales of houses in London bitcoin or some wages in Japan paid in Bitcoin. This is not a liberating force of bitcoin. It is not more in our eyes than communication to maintain the phenomenon.