The reason which mostly affect bitcoin is trader, there are so many trader makes panic selling and buying. Bitcoin must adopted by more people to minimize it's volatility.  A big trade will have a smaller price impact, hence a smaller price volatility.who get some profit from it they try to book the price and try to sell their bitcoin and so the supply increases and thus the price decrease and i think that this will continue for a long time because still a lot of people have o join the world of bitcoin.