Here you need to consider investors and traders separately. That you wrote can be applied to investors. Again, with the reservation that the project is not stupid and not a sham.
If we talk about traders, they sell and earn at any indications of the course, and at the bear market and bull market. Sometimes I really envy the traders.
If you envy traders and think you could earn greater profits if you traded your coins with more frequency then become a trader but remember the potential profits of traders are higher than the profits a long term holder can get but at the same time the losses can be way bigger as well and that is why I prefer to be long term holder since I prefer to not take such high risks.