Everyone buys bitcoins every time, people buy it when it reaches a new ATH and people sell it when it's at its lowest. There are moments when you think who would buy it or who would sell it right now but people always make decisions.
From my understanding, some people risk to buy Bitcoin when its price is high because they are day traders and want to make a small profit in a short timeframe, i.e. someone buys Bitcoin at 50K, thinks it will rise at least up to 51K, sells there and that's all but there is one unlucky day when market crashes, bears take the edge and this plan fails.