Casa is a premier self-custody security platform designed to protect Bitcoin and Ethereum holdings through innovative multi-signature (multisig) vault technology. Founded by Nick Newell and Jeremy Welch, the company has built a strong reputation for making institutional-grade security accessible to individuals. Their flagship product uses a multi-key approach"typically 2-of-3 or 3-of-5 multisig setups"distributing key management across multiple devices and geographic locations, dramatically reducing single points of failure. Casa also offers inheritance planning solutions, addressing a critical gap in crypto custody. The mobile app provides a clean, intuitive interface that simplifies what is traditionally a complex security setup. However, Casa operates on a subscription model with premium tiers that may be cost-prohibitive for smaller holders. It's worth noting that Casa is primarily a cold storage/vault solution rather than a hot wallet, so daily transaction convenience is limited. The platform supports only Bitcoin and Ethereum, which restricts its appeal for multi-asset portfolios. Despite these limitations, Casa remains one of the most trusted names in personal crypto security, ideal for high-net-worth individuals prioritizing robust self-custody.