A system and method for passive real-time order state replication and recovery. Upstream data is received from an upstream system via a reliable transport, the upstream data also received by a supported system. Downstream data is received from the supported system via the reliable transport. Data acknowledgements are received from the supported system acknowledging receipt of the upstream and downstream data. A replicated current order state of the supported system is continuously updated in real-time based on the received upstream data, downstream data and the data acknowledgements. A recovery request is received after the supported system has experienced an outage. The current order state is restored to the supported system by transmitting a recovery message to the supported system containing the replicated current order state.