In a wide financial space, can your exchange guarantee a high level of security?
Usually, cryptocurrency exchanges have the highest level of security, I don't think COINSBIT is an exception.
Even if they have high security level, they are still vulnerable to potential attacks. Softwares nowadays are getting sophisticated so it is only a matter of time when those hackers will use the appropriate tools to attack their walls. So if you are a crypto user, never store your coins in exchanges for long term. Better store it in your own wallets.