The price is based on supply and demand so obviously the value will be always volatile and that is the reason why we should just hold our coins and do not sell it immediately.
It has always been based on the law of supply and demand but also the law of supply and demand is affected with the market trends because there are people who decides to sell due to certain reasons like sudden Government regulation, that will affect the price and force the it to go down, but if a group of people buys the coins because the price is low, then it will create a sudden demand which will help the price to go up.