It is plenty of companies who lost more than 30 - 50 percent of their total value and they are still in here. They recovered back again and no one knows how.
The same happens with bitcoin, it will recover eventually at some point. It is going up again.
Every market like stocks commodities Interest rates etc see corrections upto 75 % which doesn't mean that they will not go back up higher and history proves otherwise. These corrections in fact are healthy. There can be many many factors behind these moves.