Electrum functions as a hot wallet or cold storage. Instant On Electrum is fast, because it uses servers that index the Bitcoin blockchain. The Trezor wallet works with multiple currencies and works as a password manager, two-factor authentication device and other useful features. Its mission is to develop, package and distribute Electrum software, and to provide services to Bitcoin users and businesses. Best for Security: Trezor. It also allows for anonymity and keeps your Bitcoin in your pocket or bag pretty much everywhere you go. Your wallet is never down.