You can not panic. Panic can lead to very unpleasant consequences, when carelessly to sell its assets at an unfavorable price. By investing should be approached wisely.
but this is really happen in market when many traders see that the price is going down or going up. many of us can not controlled our feeling of panic so its giving a bad effect for our trading and we can not make profit but only get loss because we make cut loss fast before we realize that is just down for a second and then the price is going up for sure.
That's why many of us fell to hold our assets in the long as we do panic when the price fall badly, but it's a different scenario for bitcoin as it is its nature to pump and dump, just hold tight when you see that because it will just measure how deep your trust with bitcoin. Remember, most of the successful are those who are holding in the long run.