It happens again. Unfortunately it seems that the managers of the exchanges (some) do not learn the importance of security, or they leave it in the background, I think again that the problem comes again from security budgets, sometimes lower than marketing budgets, for example. What has happened to BitMart (unfortunately it won't be the last hacked exchange) is another way of teaching the community that coins/tokens should never be stored on an exchange.
I hope that the management of the company has good insurance to be able to replace all the funds stolen from its users and that people learn not to leave their funds in any exchange.