I know people who engaged in this practice and at first it looked like good business and easy money but as time progresses, they usually come back to face reality which is that they have ran out of Bitcoin or have their Bitcoin portfolio depleted with no way of accounting for the profits made. This happens in two ways, the first of it is that when they buy during bear market and sell during bull market, some usually keep this money in their bank or in stable coins and every now and then they will always see a need and will use part of the money to meet such needs. This will continue until the money is seriously diminished. The other way this happen is that they shift their profits from Bitcoin to shit coins with the believe that after the bull season comes the altcoins season. The end of with stories most of the time and I see this as similar to gambling.

There is a high probability that someone who buy and sell across seasons might encounter problem which can have serious impact on his overall portfolio. Instead of this pattern, holding across seasons is better, because those that have been holding since 2013 are heavily in profits now, and same can be said of those that have been holding since 2017 and so on. Bitcoin always gets better with time.