Auctioning mechanisms for dark order block trading

A computer system comprising:

• a processor operatively coupled to a memory, the memory storing instructions that, when executed by the processor, cause the computer system to:
• initiate an online auction, the online auction having a duration that is unknown to market participants;
• receive one or more firm limit orders from one or more computer devices associated with the market participants;
• store, in an order book within said memory, a first portion of the one or more firm limit orders, the first portion received during the duration of the online auction;
• prevent storage, in the order book, of a second portion of the one or more firm limit orders, the second portion received after the duration of the online auction;
• remove, from the order book, one or more ineligible firm limit orders from the first portion based on a reference price;
• and
• execute a remainder of the firm limit orders from the first portion stored in the order book.