This was a Chinese cryptocurrency exchange, it held a utility token within its platform that currently has no value and is basically not used by anyone.
At the time it had 15 trading pairs, with some currencies that were really unknown as well as this exchange. It had good commissions for both operators and when making withdrawals.
In many price verification sites it is possible to verify that Oex is out of service, without volume or active website, the most striking thing is that there is no data about a possible exit from the market or anything official closure by this exchange. And of course when accessing its website we can verify that it is "out of service".