If you wish to hold some coin then use exchange only for during exchange. Just exchange your coin and transfer on your personal wallet that you have controlled. Specially you can use hardware wallet.
Because many exchange hacked buy hacker. Many people loss their capital by hack.
So please don't hold your coin on exchange for long time.
The only problem about exchangers is that, sometimes they are penetrateable or maybe
there is a monkey business on their own system which they tell users that there is a bug just to steal the coins of other investors and that is the reason why we should not place our coins for a very long time.
If they wanna steal your money they'll do it regardless of how long you hold your money on the exchange. They can just say that the transaction doidn't go through and that's that.