Warm Wallet

A warm wallet is the tier a custodian keeps between its hot and cold storage: keys that are not exposed to a live internet-facing service, but are reachable by an operational process fast enough to refill the hot wallet during the day. The reason the tier exists is that the two extremes do not cover the requirement on their own. A hot wallet large enough to fund a busy day's withdrawals is a large sum sitting where a compromise reaches it; a cold wallet that requires a scheduled ceremony cannot be drawn on inside an hour. The warm tier absorbs that traffic under stronger controls than the hot one — typically several approvers, address allowlists and value limits per movement — while accepting that it is more reachable than cold. Terminology is not standardised and the boundaries differ by operator, so a claim that a given percentage is held in cold storage is only meaningful if the operator also says what it counts as warm and how it is controlled.