i'd be really suprised for any of the 3 biggest exchanges to go out of business...the profitability of running a popular bitcoin exchange must be enormous considering the steep trading fees they charge.
You're assuming they maintain 100% capital reserves. All that money.... It's hard to imagine they would just leave it in customer accounts and not "invest" any of it in new servers, hosting, employees, software, security consulting, DDOS protection, legal services, physical security, or hell, even 30 day t-bills. The costs of running a major BTC exchange have skyrocketed along with the price & volume. High on their own success it's not hard to imagine they aren't thinking really big and trying to scale faster than their commissions can drive them. It's a race the top, after all. No one wants to trade on the #2 exchange. It would take an organization with considerable discipline and integrity to resist the temptation to borrow customer funds to scale the business when the alternative is failure. I mean hell, it's LEGAL for banks to do it - why shouldn't a BTC exchange, right? ...then boom, 50% price drop, and oops, customers try to pull out their USD/EUR, and hmm.... well, we're a little short on fiat today... Let's just put a hold on fiat transfers and let the market calm down for a couple weeks, and we'll pay everybody then. We're not bankrupt, we're just low on cash TODAY, after all. ...Then the volatility continues, some more bills come in, a few more customers cash out, and BAM liquidity crunch - Bankruptcy. ...and the first 21st century crypto-currency "run-on-the-bank" happens. Standard banks went through this in the 17/1800's and now they must PROVE their capital reserves every night to the Fed. With BTC, this is just waiting to happen.
