Everyone was really shocked about the sudden drop of bitcoin's price from $11,000 because some miners already sold their holdings. It is also normal for bitcoin to make this kind of sudden decrease or increase to its price due to its volatility, that is why it is hard to predict bitcoin's price. Also, if you are a long-term holder you shouldn't be worried because you should take this as an opportunity to buy more bitcoins to earn more profit in a long-term.