US Patent 8108289 Market data recovery

Networks, systems and methods for recovering data messages from a market data stream and for building a book for a financial instrument are disclosed. An out-of-band data stream related to an as-of state of the market for one or more financial instruments is distributed parallel to a stream of market data for the financial instrument. The as-of data stream is referenced to the financial according to a unique identifier of the messages of the market data stream. The as-of data for a financial instrument may be provided at periodic rate that may be varied according to one or more factors.