If I'm in for long term on a coin, whether prices are declining at the moment, I don't panic sell. For my trading, I usually set a stop loss usually -5% , once it gets to that price, it sells auto to prevent further loss, then I think about buying back when need be. Panic selling when you see price declines is not always the best option.
Yep, your option is kind of unresonable guy. Personally, it's up to each person, if they can not control their emotion, they better choose to sell in order that they can get rid of both panic and loss. Honestly put a stoploss is an effective measure in this context. Because it can minimize investors' loss. To say frankly, most people tend to be not calm and patient while they are facing a decline. But anyways, avoid panic selling is much better.