A good trader doesn't buy back at the exact position where he has sold his assets to withdraw the profits, that is done only when the price drops below that point, and only if the trader has sold the assets earlier only to buy back when the price dumps, otherwise, they might not even buy again. If they wish to buy back, they will probably wait for the correct time to buy again so that they don't lose back the earned profits.

A novice trader or someone who is always hit by FOMO (fear of missing out) might make the mistake of selling for profit and then buying again at the same time when the price didn't even go down. That can be a costly mistake and might only work sometimes when the market actually goes higher than where they've sold earlier.