Under the rules of the current world that we live in, administrating any form of financial business requires approval and requires the so-called institution to register with the respective financial authority of the country it is residing in. In well known cases this can be FSA (UK), SEC (USA) or any equivalent financial authority.

Operating an exchange platform would mean that money has to move through it (third party funds) and stored on a medium of exchange (a bank) which would be operating in a country (thus being regulated by a financial authority).

Therefore I dont see how anyone successfully, long term, and stable (from a regulatory point of view) would be able to operate without downtime.