There are times when I have sold at a loss (a small loss), in order to move to a coin that I knew was going to go up.
If I sell at a 1% loss, but put that money into a coin that goes up more than the 1%, then I am fine with that, but that does create risk for sure.
In my last case, I sold Litecoin at a 2% loss, but I bought BNB, and it went up 50%

That being said, I do have some money in BTC right now, that will be sitting there for quite awhile, because of the drastic dip that took place.