Just as you said there are some coin you will buy, if you don't exit the trade, you will run at loss. There was a coin I bought and it gave me about $10 profit. and after the coin percentage was high, I felt this will fall in no less time. So I decided to sell and wanted to involve buying another coin that was pumping if it will just pump a little. So I decided to watch how the coin is Making it move, after some minutes it fall by %100. I was shocked. and had it been I baugh it, I would have loss both my capital and my $10 profit. So we should just be careful with the kind of investment we make.
That is if the coin you buy is highly risky, but if not, you can try to be calm and HODL them a little bit because for sure they can always recover. I have seen lots of traders who are doing this. Just don't only set a stop loss so that your coins won't be liquidated automatically once the price drops equivalent to the amount that you have set.
Entering a moving a train is risky, so you shouldn't be buying a coin that is already pumping because there is a big chance that the pump will stop and turned into a dump, as those old investors of that coins is already selling or someone is only manipulating it if it's a high-risk coin. When you are profiting, you should pull out of most it together with your capital. That way you won't feel like a total loser, just in case you got a bad trade.