when we are using the Bitcoin continuously then it will not been stable for a long time in a same position that is the most important reason that we don't have the prediction about the Bitcoin in any situation and more over normal will reduce the value or increase the value.
Obviously, with its volatility, that would be hard.
Demand and its investors are the most reason why the price of Bitcoin do change and not change. It is more of it changes that it do not change since as I said, with its volatility and a lot of its users, Bitcoin will change so quickly.