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 like electrum and Hodler wallet?
We can hold our coin in exchanger, or our wallet. But If we keep on exchanges, then We have to choose the trusted exchanges. Or we can keep our wallet example coinbase, blockchain or if we keep ERC-20 coin then we can use myetherwallet.