For me,selling bitcoin is not stupid,if they sell there bitcoin in low price it is better to buy bitcoin to have some more profits if the price is going back again bacause once you buy bitcoin in lower price if he value was came back it its vary worthit because you have a good profit.
If it is stupid then for sure all of us are just holders of it, but for some who are engaging their time in the market are doing a day trading or holding bitcoin for just a short period of time, but for me we should be balance that we should just hold a single of it and doing trading at the same time.