Are There Hybrid Models That Combine Features of CLOB and RFQ Systems?

Yes, hybrid models that combine features of CLOB and RFQ systems exist, often called "workup" or "click-to-trade" protocols. These systems may display an indicative order book (like a CLOB) but require participants to initiate an RFQ-like interaction to finalize a trade at a firm price.

Another hybrid model involves a CLOB for small, standard-sized trades while directing larger block trades to a separate RFQ protocol. This allows the market to benefit from the continuous price discovery of a CLOB while providing a safer mechanism for executing large orders without market impact.