I have a friend who is into Long term Bitcoin investment when ever he holds his Bitcoin and Bitcoin hit a certain price he was always tempted to sell little and he will, that was how it was for him until he decided to have a price target which he wants to reach with Bitcoin and that was how the temptation to sell when ever there was an increase in Bitcoin price stopped.
So I think having a price target with Bitcoin will help you hold your Bitcoin very well without the feeling of selling, it will increase your patience level.
Your friend was a scalper and not a long term investor of bitcoin as you called him.
I disagree on this, though you are right that his friend is not a long-term investor but he's also certainly not a scalper. If you read the definition of scalping, you will understand this well, and I've never heard of scalping in investing but in trading.
What the guy engages in is not totally condemnable, as the practice, if used well will deliver massive success into his account. I don't buy the idea of keeping my Bitcoin for so long again, I invest and divest at the right time to maximize my profits. I've two portions of Bitcoin investment, I HODL some since 2022 and I started investing and divesting the other part regularly since last year. I tell you, the one I regularly invest and divest has grown so much more than the one I HODL.
It's practical, but one thing the guy's friend is doing wrongly is not knowing the reason why he divested but just acting emotionally.