X0206 3 2019-04-04 0 0001758730 Tradeweb Markets Inc. TW 0001771935 Blackstone Management Associates (Cayman) VII L.P. C/O THE BLACKSTONE GROUP L.P. 345 PARK AVENUE NEW YORK NY 10154 0 0 1 0 0001771947 BCP VII GP L.L.C. C/O THE BLACKSTONE GROUP L.P. 345 PARK AVENUE NEW YORK NY 10154 0 0 1 0 0001404073 Blackstone Holdings III L.P. C/O THE BLACKSTONE GROUP L.P. 345 PARK AVENUE NEW YORK NY 10154 0 0 1 0 0001478809 Blackstone Holdings III GP L.P. C/O THE BLACKSTONE GROUP L.P. 345 PARK AVENUE NEW YORK NY 10154 0 0 1 0 0001478815 Blackstone Holdings III GP Management L.L.C. C/O THE BLACKSTONE GROUP L.P. 345 PARK AVENUE NEW YORK NY 10154 0 0 1 0 0001393818 Blackstone Group L.P. 345 PARK AVENUE NEW YORK NY 10154 0 0 1 0 0001404071 Blackstone Group Management L.L.C. C/O THE BLACKSTONE GROUP L.P. 345 PARK AVENUE NEW YORK NY 10154 0 0 1 0 0001070844 SCHWARZMAN STEPHEN A C/O THE BLACKSTONE GROUP L.P. 345 PARK AVENUE NEW YORK NY 10154 0 0 1 0 Class B Common Stock Class A Common Stock 96933192 I See Footnotes Class D Common Stock Class C Common Stock 22988329 I See Footnotes Non-voting common units of Tradeweb Markets LLC Class A Common Stock 22988329 I See Footnotes Shares of the Issuer's Class B common stock ("Class B Common Stock") have ten votes per share and are exchangeable for shares of the Issuer's Class A common stock ("Class A Common Stock") on a one-for-one basis at the discretion of the holder. These exchange rights do not expire. Shares of Class D common stock of the Issuer ("Class D Common Stock") have ten votes per share but no economic rights (including rights to dividends or, other than their par value, distributions upon liquidation) and are issued in an equal amount to the number of non-voting common units of Tradeweb Markets LLC, a subsidiary of the Issuer ("LLC Units"), held. Shares of Class D Common Stock are exchangeable for shares of the Issuer's Class C common stock ("Class C Common Stock"), which have one vote per share but no economic rights (other than their par value upon liquidation), on a one-for-one basis at the discretion of the holder. These exchange rights do not expire. Pursuant to the terms of the limited liability company agreement for Tradeweb Markets LLC, LLC Units may be exchanged for shares of Class A Common Stock or Class B Common Stock, in each case, on a one-for-one basis at the discretion of the holder. Upon such an exchange, a corresponding number of shares of Class D Common Stock (or shares of Class C Common Stock, in the event the holder exchanged its shares of Class D Common Stock as described above) will be canceled. These exchange rights do not expire. These securities are directly held by Refinitiv Parent Limited. These securities are directly held by Refinitiv US PME LLC. Refinitiv US LLC is the controlling member of Refinitiv US PME LLC. Refinitiv US Holdings Inc. is the sole member of Refinitiv US LLC. Refinitiv Parent Limited is the sole shareholder of Refinitiv US Holdings Inc. Refinitiv Holdings Limited is the sole shareholder of Refinitiv Parent Limited. BCP York Holdings (Delaware) L.P. is the majority shareholder of Refinitiv Holdings Limited. BCP York Holdings GP (Delaware) L.L.C. is the general partner of BCP York Holdings (Delaware) L.P. BCP York Subsidiary (Cayman) L.P. is the sole member of BCP York Holdings GP (Delaware) L.L.C. BCP VII Holdings Manager (Cayman) L.L.C. is the general partner of BCP York Subsidiary (Cayman) L.P. Blackstone Management Associates (Cayman) VII L.P. is the managing member of BCP VII Holdings Manager (Cayman) L.L.C. BCP VII GP L.L.C. is the general partner of Blackstone Management Associates (Cayman) VII L.P. Blackstone Holdings III L.P. is the sole member of BCP VII GP L.L.C. The general partner of Blackstone Holdings III L.P. is Blackstone Holdings III GP L.P. The general partner of Blackstone Holdings III GP L.P. is Blackstone Holdings III GP Management L.L.C. The sole member of Blackstone Holdings III GP Management L.L.C. is The Blackstone Group L.P. The general partner of The Blackstone Group L.P. is Blackstone Group Management L.L.C. Blackstone Group Management L.L.C. is wholly-owned by Blackstone's senior managing directors and controlled by its founder, Stephen A. Schwarzman. Due to the limitations of the electronic filing system certain Reporting Persons are filing a separate Form 3. Information with respect to each of the Reporting Persons is given solely by such Reporting Person, and no Reporting Person has responsibility for the accuracy or completeness of information supplied by another Reporting Person. Each of the Reporting Persons (other than to the extent it directly holds securities reported herein) disclaims beneficial ownership of the securities held by the other Reporting Persons, except to the extent of such Reporting Person's pecuniary interest therein, and, pursuant to Rule 16a-1(a)(4) under the Securities Exchange Act of 1934, each of the Reporting Persons (other than to the extent it directly holds securities reported herein) states that the inclusion of these securities in this report shall not be deemed an admission of beneficial ownership of all of the reported securities for purposes of Section 16 or for any other purpose. BLACKSTONE MANAGEMENT ASSOCIATES (CAYMAN) VII L.P., By: BCP VII GP L.L.C., its general partner, By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer 2019-04-04 BCP VII GP L.L.C., By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer 2019-04-04 BLACKSTONE HOLDINGS III L.P., By: Blackstone Holdings III GP L.P., its general partner, By: Blackstone Holdings III GP Management L.L.C., its general partner, By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer 2019-04-04 BLACKSTONE HOLDINGS III GP L.P., By: Blackstone Holdings III GP Management L.L.C., its general partner, By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer 2019-04-04 BLACKSTONE HOLDINGS III GP MANAGEMENT L.L.C., By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer 2019-04-04 THE BLACKSTONE GROUP L.P., By: Blackstone Group Management L.L.C., its general partner, By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer 2019-04-04 BLACKSTONE GROUP MANAGEMENT L.L.C., By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer 2019-04-04 /s/ Stephen A. Schwarzman 2019-04-04