Mr. Simmons serves as a director of Invivoscribe, Inc. and Stonetex Oil Company, privately held companies. From February 2001 to June 2003, Mr. Simmons served first as Chief Executive Officer and then as Chairman and Chief Executive Officer at The NASDAQ Stock Market Inc. From May 1991 to December 2000, Mr. Simmons served as President and Chief Executive Officer of Prudential Securities Incorporated.