Well, it really depends on the person! Everyone has their own choices to make. Some Bitcoin enthusiasts, known as "maxis," hold onto their Bitcoin even during a bull run because they have a long-term vision and commitment to BTC. On the other hand, there are "profit maxis" who buy Bitcoin with the intention of selling at the peak of a bull run and then buying back when the market turns bearish. Personally, I believe it's not necessary to sell all your holdings. Since it's hard to predict the exact top or bottom of the market, it's better to take out your initial investment and a good amount of profit, and let the rest continue to grow. Whatever happens in the future is, well, for the future!
Indeed, it really depends on each investor's strategy and plans. some people will sell all their bitcoin and try to buy it back when the bear market comes, some people will not sell or only sell a little because they have not reached their set goal. personally, I would sell everything rather than keep it because I have my own plans, I think it would be unwise to hold on to some during the bull season when we can buy it back cheaply during the bear season. so selling half or selling all is really up to each person.