The Exchange has filed proposed rules with the Securities and Exchange Commission to implement its new trading model. This model will allow Exchange participants to interact in a fully-automated matching system. The Exchange will no longer operate a physical trading floor where on-floor specialists, brokers and market makers seek execution of their orders. Instead, the Exchange will operate an automated
system where its participants – from any location – can submit orders for immediate execution. The Exchange believes that this new model provides an opportunity for its participants and their customers to receive efficient executions within a framework that complies with Reg NMS.

CHX's SEC filing of the proposed new rules for the new trading model, 2006-05. (note: PDF is 432 pages long)

Brief overview of the proposal. (in PDF)

Proposed Rule Changes. (in PDF)