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.
Yes i was lost my 135 tokens and it price was more 20k$ .Bitrex and binance most safe and secured exchanger so i think never join or trade other exchangers without knowing more details about. Most of the people lost and hacked for click pshing site which looking like original so be carefully
true store your coin in a trusted exchanger so it would ever be safe cause taking this in other exchange that you may never knowing the details of it you might be lost it for.