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.
We should not keep coin and long-term investment, the market is falling into crisis as the price of bitcoin is constantly decreasing and consequently the price of altcoin drops sharply, so long investment At this point, you will only get a loss and you will be able to lose a lot if the market can not recover and continue to fall deeply.