This kind of advise or thing is being discussed for hundred of times into this forum which this should really be a basic thing or habit that most traders or investors of certain coins shouldnt really consider to make it as a main wallet where we do store up our coins.If we do see out on previous years where exchangers is being hacked how you would able to see those people who mourn and cry coz they lose up lots of money since their coins is on that exchange? You cant do anything about it when it comes to recovery since you dont possess the private key that would always be the possible consequences.