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?
for recently, I only saved the assets of bitcoin and altcoin on exchangers, although not in large numbers but often it made me worry because just relying on security alone is not enough. If for example I want to save it in a personal wallet, if I suddenly want to sell it, it will also be quite difficult for me