The people going bankrupt in this game is the people who are investing money from debt/loans/credit cards into Crypto currencies. You cannot fund Crypto currency investments with debt, because it is a long-term investment and you have to repay that debt monthly. So if you not making a profit every month, you then have to pay that debt out of your own pocket. 

These guys cannot hold onto their investment for a long time and they start losing money, so they sell prematurely and mostly at a lower price than what they bought it at. That is where people are making their mistakes.