Watch-Only Wallet

A watch-only wallet is loaded with an address or an extended public key but no private key, so it can display balances and history and even build an unsigned transaction, yet it cannot authorise anything. The setup separates monitoring from spending: a phone can show a portfolio in real time while the signing keys stay on an offline device or inside a hardware wallet. It is the usual companion to cold storage and to multisig arrangements, and it also lets an accountant or auditor follow activity without ever touching custody. One caveat is privacy rather than theft, because sharing an extended public key exposes every address derived from it to whoever holds it.