first of all erace that mentality from your mind because it's not possible with bitcoin, i may not say about other cryptocurrencies since most ended as a result of failed projects, it your bitcoin disappeared then i think you were hacked or scammed due to your carelessness and we have many people that have been a victim of that, but bitcoin "can not" go down to 0 as you thought because its not a shitcoin, and whenever there's a dip in bitcoin price speculation, investors find it joy to invest because of the certainty to rise after somewhile.