Nasdaq is looking to patent a way in which a blockchain can be used to record exchange transaction records.
On 6th October, the US Patent and Trademark Office (USTPO) released an application for “systems and methods of blockchain transaction recordation”, originally submitted by Nasdaq on 31st March. It is attributed to Tom Fay, Nasdaq’s senior vice president of enterprise architecture, and Dominick Paniscotti, associate vice president for enterprise architecture.
Essentially, the application details an exchange system comprising digital wallets, an order book and matching engine, with a "closed blockchain" utilized as a record of transactions that is updated in real-time as participants act.
http://www.coindesk.com/nasdaq-patent-application-blockchain-backup/