Well, a lot of people will keep some $$$ and some cryptocurrency in their account at the exchange. Maybe because they want to play the day trader, being able to

Well, a lot of people will keep some $$$ and some cryptocurrency in their account at the exchange. Maybe because they want to play the day trader, being able to buy and sell at a moment's notice. So the exchange ends up with a big account of client funds containing cash, and a big wallet of clients' cryptocurrencies. If a bit of that money goes missing, they can cover it up for a long time, if cryptocurrencies are growing and there's net more money flowing in than flowing out. You just pay departing customers' withdrawals from new customers' deposits. It is only when the tide goes out we find out which swimmers have lost their trunks. And once a company's demise becomes inevitable, perhaps insiders decide to help it along. If you've already been hacked for $10 million, why not make it $100 million given the company's going under anyway and you'll be the prime suspect?