It's better not to give advice to this kind of problem because in the end when our advice is contrary to what happened we are the one to blame. Just say to your friend that it is up to him to decide whether to hold or sell his crypto.
I really agree with you, because here about trading someone's luck, because when we give advice to hold it, then in between other times he really needs money suddenly and the market price at that time is also low, that's when you will lose. trust your friends