The Clearing Corporation Finalizes Purchase of onExchange.

Chicago, August 19, 2004 - The Clearing Corporation (CCorp) today announced finalization of its purchase of onExchange Inc. (ONX), a derivatives and securities trade-processing technology software vendor headquartered in Lexington, MA. The acquisition will broaden CCorp's array of products and services as it expands its business into more diverse and global markets.

Dennis Dutterer, Clearing Corporation CEO said: "We are pleased to incorporate onExchange into The Clearing Corporation. The combination of onExchange's derivatives market technology with CCorp's innovative clearing systems will enable us to expand our technology solutions into the global marketplace."

The acquisition of onExchange and its software systems includes the Extensible Clearing System (ECS), which is licensed by New York Clearing Corporation (NYCC) for the New York Board of Trade (NYBOT), the New York Mercantile Exchange (NYMEX), the London Clearing House (LCH), and Hedge Street. CCorp's purchase also includes onExchange's two subsidiaries, onExchange Board of Trade, Inc., and onExchange Clearing Corporation; although dormant, the former has been approved as a DCM (designated contract market), and the latter has been approved as a DCO (derivatives clearing organization) by the Commodity Futures Trading Commission.

About The Clearing Corporation
The Clearing Corporation, a stockholder-owned, Delaware corporation now in its 79th year of business, is the only active independent futures clearinghouse in the world. Additional information on The Clearing Corporation is available at www.clearingcorp.com.

Contact: Andrew Yemma, Intermarket Communications, 212-888-6115, ext. 225