this case often happens to me, many of my friends always suggest whether their coins are more appropriate to hold or sell, I sometimes always find it difficult to give advice, I just say "if your capital is still losing it's best to hold it until it returns capital, and if it is profitable, sell it up to 10-20% profit"
It's really hard to answer if someone asks something like that, afraid to get the wrong answer because we don't know what the future will be like and we have to answer correctly so as not to disappoint people. I agree with your answer, if you still lose, it's better to hold on until the price goes up again, but I'm also confused if the price keeps going down