I would say that the stupid ones are the one who sell at the dip. The smart ones are the people who sell at the peak price, it is not easy to identify the peak price. And then these people buy at the dip, hence they got more bitcoins.
in my opinion do not need to wait when the price has peaked new sell it, the most important is when the price has reached the target of each holder to get profit no need to take a big profit. if waiting for the high price it must be very patient.