The biggest mistake anyone can do is still holding unto their altcoins when bitcoin touched 60k weeks ago and still holding strong when the fall began weeks ago, imagine someone still holding HEX token when the coin did 40x already? If you are someone like this friend I don't know what your aim is but sorry to say you are doing it wrong. Check yourself cos it's possible you are struggling with greed.
I think I see some still holding even the price have made that far, its because they believe the coins are undervalued, and it's true some are, especially if the coin has a product, or for example a coin, where they use the coin to buy something in the game, or staking, the point is if you can earn while holding it, why you are going to sell it, but if you are talking about a coin who just pop up out of nowhere, that's a different story.