Cryptocurrencies should be stored in a secure wallet, either an online wallet, mobile wallet, desktop wallet or a hardware wallet, depending on the type of cryptocurrency you are holding. Hardware wallets provide the most secure way to store cryptocurrencies, as they are typically offline and not connected to the internet. It is important to keep your private keys safe and stored somewhere secure, as this is how you access your wallet. It is also important to back up the wallet data, in case you lose access to it, and to use a strong password to protect from unauthorized access.