It all depends now on a lot of factors, most of people who invest on bitcoin at 20k$ or over 15k$ lose trust and they wait for a boom, and also who want invest before not want because they now don't believe on crypto now, and also depends now on regulation, but in my opinion there is some chance to boom again, but this time only strong projects who have support for real use will grow.
Those who invested in bitcoin when it was in pump phase did that on their own freewill and greed. They just saw it making progress and took action without even trying to make some research of their own. It is not like that they have made some wrong decision by investing in bitcoin but it is suggested to not invest during the rise. It is also pointless to cry because bitcoin will be rising up soon.