Hey there!
A question of panic selling was already discussed on this forum a billion times. But whats bad here? If you are sure that the price will grow back then you can just buy some BTC in better rates. The more dangerous will be the situation when someone is buying BTC while being afraid of loosing some profits despite the fact that pump has already happened (I'm calling it a panic buying). Thats seems like a straight way to lose money and make a bubble.
I am not an expert in trading and I don't even try it with exchanges because most of the time I am into long term investments. For me panic selling and panic buying are most likely to happen to newbies and Altcoin traders. It had happened with me before when I was new to cryptocurrency I decided to sell all my Altcoins because I was afraid price would continously go down but I am not affected with my loss since I only have small amount of Altcoins. Those experiences serves as a lesson learned to me though a good try also in investing in Altcoins. In terms of Bitcoin investments, panic selling and panic buying are not likely to happen.