Professional Cryptocurrency traders say to not keep crypto on exchanges and there is a great reason for that.
All though the blockchain is very difficult to disrupt or hack, exchanges are centralized and lack those properties.
From the very start one of the biggest exchanges at the time Mt. Gox got hacked and collapsed and with it the price of bitcoin.
Fortunately solutions are being delveloped on the horizon, The DEX !
Decentralized exchange's that runs on blockchain, there are many out there but one that I have lots of faith in and is going to get an update very soon is the waves DEX built into their light client and apps for android and IOS .
The link to the article about he hack is right bellow.
https://bitcoinist.com/youbit-bankruptcy-hackers-assets/