We don't know when to do this and this is the problem with trading speculative assets. You can make a decent return by deciding WHEN you want to pull out price wise or coin wise - last bull run i pulled some when we were half down from the ath (was still a decent gain).
Realistically i think if bitcoin starts to fall and the dominance follows suit (falls to 60% or something) its probably a good idea to sell. I'm not sure if anyone's checked but a little after bitcoin reaches a peak (say 3 days) if trading sideways, you might make more converting to alts and waiting for the sideways continuation to be over.
I did the same in 2017 back when I was still trading. I came into the market thinking 2x gains are something we all dream of so naturally, being a trader used to selling at 10% gains I was surprised by Bitcoin and its 100% weekly moves.
I kept looking for a resistance line, measuring candles and so on and every time I'd sell and it would go up the next day, so I'd buy, hold for a day and sell again over and over again from 5 to 16 thousand when I finally gave up thinking it could not be real.
We'll probably have a number of corrections in this bull market, like we had in the last one. If we were to fall today back to 29000 it would be such a correction and we'd probably continue to go up from there towards 40000.