Cryptocurrencies can be kept online or offline. If the cryptos are kept on the exchange platforms or other online platforms, it can be lost due to hacks.
So it is important to choose the best wallets that are safe and secure. Please help me in choosing the safest cryptocurrency wallets
The Answer to this question will vary from users to user.
From my personal experience many wallets are trusted, and if you are a day to day trader then oftenly try to convert the BTC to Fiat when necessary.
I have used many wallets, and are also impressed by many of them.
Generally i prefer keeping the coins in online wallets.
Some great wallets are BlockChain Wallet, CoinBase and Coins.ph(lowest fees).
Hope this will help you OP.