Their are many reason behind falling price of bitcoin. And some the important reason are its decentralised nature because of this it is ban in many country. And Because of this nature it does not under control of any kind of authority or government. And this is the main reason behind its ban. Another reason behind its falling price is its irregularity in its production and distribution. When bitcoin doesn't supply according to its demand then their is downfall shows in its price. Another reason behind this is its complex nature to understand.