Coins should always be considered in a safe storage, there are lot of wallets and platform that could be used to hold coins, both of this has good side and bad. Where will you choose to store or hold your coins, in a close source wallet (exchanges) or an open source wallet?
Many of people are saying that it is not good to hold your coins in an exchange and they are saying that these exchanges are not safe they can be hacked any time or any other issue can happen to it. It is better to hold your coins in your offline wallet which is more safe than any online wallet.