Tradeweb Markets Inc.

(a)Amendment and Restatement of Bylaws

On April 29, 2026, in connection with a periodic review of the bylaws of the Company, the board of directors approved and adopted an amendment and restatement of the Company’s Amended and Restated Bylaws (as so amended and restated, the “A&R Bylaws”). The A&R Bylaws became effective immediately upon approval by the board of directors.

Among other things, the amendments effected by the A&R Bylaws:

•add notice procedures for adjournments of virtual meetings of stockholders and eliminate the requirement that the list of stockholders be open to examination at meetings of stockholders, in each case, in accordance with 2022 amendments to the Delaware General Corporation Law (the “DGCL”);

•update certain procedural requirements related to director nominations and other proposals of business by stockholders in light of Rule 14a-19 under the Exchange Act and reflect certain other related changes, including: (1) requiring (i) additional background information and disclosures regarding stockholders proposing director nominations and other business, (ii) D&O questionnaires and certain representations from director nominees proposed by stockholders, including regarding compensation arrangements, indemnification, voting arrangements and compliance with applicable policies and (iii) certain disclosures regarding other persons related to a stockholder’s solicitation of proxies; (2) requiring that any stockholder submitting a notice of nomination or other business (i) make a representation and provide confirmation as to whether such stockholder intends to solicit proxies in support of the proposal, or in the case of nominations, in support of director nominees other than the Company’s nominees in accordance with Rule 14a-19 under the Exchange Act and the A&R Bylaws, and (ii) provide evidence that the stockholder has complied with such requirements; and (3) making clear that stockholders cannot nominate more directors than are to be elected at the applicable annual meeting;

•require that a stockholder directly or indirectly soliciting proxies from other stockholders use a proxy card color other than white, which is reserved solely for use for solicitation by the board of directors;

•add Article III, Section 13 relating to emergency bylaws if a quorum cannot be readily convened for a meeting of the board of directors in the event of an emergency (as defined in the DGCL); and

•make certain other non-substantive, ministerial, clarifying and conforming changes, including updating references to Chair (vs. Chairman), adding “close of business” and “affiliate” definitions to advance notice provisions, adding a severability provision, and clarifying procedures around stockholders meetings, who can preside at board and stockholder meetings in the Chair’s absence, when stockholder votes can be disregarded, certain indemnification provisions, and certain officer provisions to provide additional flexibility.

The foregoing description of the A&R Bylaws does not purport to be complete and is qualified in its entirety by reference to the full text of the A&R Bylaws, a copy of which is filed as Exhibit 3.2 to this Quarterly Report on Form 10-Q and is incorporated herein by reference.

(b)None.

(c)Securities Trading Plans of Executive Officers and Directors

During the three months ended March 31, 2026, none of our directors or executive officers adopted, modified orterminated a trading plan intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act, as defined in Item 408 of Regulation S-K (“Rule 10b5-1 trading arrangements”) or a non-Rule 10b5-1 trading arrangement (as defined in Item 408 of Regulation S-K).