It depends on at what price the one sold his/her bitcoins. If he/she sold at 19000 dollars, they made a huge profit and they are still not in a loss.
They are still not in loss but maybe bitcoins can cross the previous peak mark but the fact is at what cost,time is money as we all know and we dont exactly know how much time will it take for bitcoin to reach that 20is thousand dollar peak again and how much time to cross that , I guess the ones who have sold out are intelligent enough because they have already booked their profit and incase anyone of those if reading this thread can now again invest in bitcoin and hold and gain a lot later.