from SC 13D
1 page
Exhibit 1 Joint Filing Agreement This Joint Filing Agreement Is Entered Into as of October 19, 2006, by and Among the Parties Signatories Hereto. the Undersigned Hereby Agree That the Statement on Schedule 13d With Respect to the Shares of Common Stock, Par Value $0.001 Per Share, of Nyfix, Inc., a Delaware Corporation, Is, and Any Amendment Thereafter Signed by Each of the Undersigned Shall Be, Filed on Behalf of Each Undersigned Pursuant to and in Accordance With the Provisions of 13d-1(k) Under the Securities Exchange Act of 1934, as Amended. Warburg Pincus Private Equity IX, L.P. By: Warburg Pincus IX, LLC, Its General Partner, By: Warburg Pincus Partners, LLC, Its Sole Member, By: Warburg Pincus & Co., Its Managing Member By: /S/ Scott A. Arenare Name: Scott A. Arenare Title: Partner Warburg Pincus IX, LLC By: Warburg Pincus Partners, LLC, Its Sole Member, By: Warburg Pincus & Co., Its Managing Member By: /S/ Scott A. Arenare Name: Scott A. Arenare Title: Partner Warburg Pincus Partners, LLC By: Warburg Pincus & Co., Its Managing Member By: /S/ Scott A. Arenare Name: Scott A. Arenare Title: Partner Warburg Pincus LLC By: /S/ Scott A. Arenare Name: Scott A. Arenare Title: Managing Director <page> Warburg Pincus & Co. By: /S/ Scott A. Arenare Name: Scott A. Arenare Title: Partner By: /S/ Scott A. Arenare Name: Charles R. Kaye By: Scott A. Arenare, Attorney-In-Fact By: /S/ Scott A. Arenare Name: Joseph P. Landy By: Scott A. Arenare, Attorney-In-Fact
