The key on here is that you should really that invest on the amount that you can afford to lose so that whenever the price neither be having some dumps then you wont really be that easily panicking out.
Of course, it is the basic principle in crypto investment. We must always invest with "the amount of money that we afford to lose". I've too many times reading this statement. 
People do really panic out because if they really having that lacks of understanding on how this market works. You will really be having that kind of impulsive approach on the time or moment that the price will really be making up such behavior.
Yep, people panic because they don't understand crypto market and its volatility. Mostly, this happens on the new comers only. People who have spent a lot of time in crypto, they must feel calm because they know it is something normal in crypto. To dead with the situation, we must ensure that we have proper knowledge. So, we understand what we must do whenever the market experiences a dump or pump.