It is so safe, as any exchange can be. The risk of being hacked, is an issue to all exchangers in principle, so do not be afraid of them. Better not to keep a lot of money on the exchange wallets, leave funds only for current operations . For example, the project in my signature, promises to pay much attention to security, but will it manage? I think yes.
But hackers do not sleep, and create new ways to steal and fraud.