You mean when we reach the stop loss limit? If yes, then it is better to sell and buy later stage.

I only put stop loss on coins which I don't have a confidence in the long run so I don't want to hold them for long. So if prices reach to the stop loss level I prefer to sell and use that money for other trades.

But for some good altcoins, I will buy and keep it and don't mind if prices go down also because I know in the long run it will go high so I may buy even more coins at that lower price.