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!