They have the resources and money to continue their operation. And if the exchange is already reputable, they have to protect that so that the hard work that they have put into it will not go into waste. There were a lot of good exchanges in the past that have lost it almost on an instant when they didn't take care of their exchange. That's why these remaining giants in the business of crypto exchange knows how to take care of themselves because the trends are quickly changing and they know that a time can possibly reverse their situation base on how they react to the demand of the market.