The Security Traders Association (“STA”) appreciates the opportunity to provide comments on the above
referenced amendments to Regulation NMS2 (“Reg NMS”) and new rules (“Proposals”) proposed by the
U.S. Securities and Exchange Commission (“Commission”) on December 14, 2022. STA was founded in
1934 and is an organization comprised of individuals who are involved in the trading of financial securities in the U.S. and Canada. Our membership is diverse, both geographically and in the roles fulfilled in the marketplace. Our comment letters on market structure are informed by a culmination of input received from a wide range of market participants and through the consequences, both intended and unintended, experienced from past changes to market structure.

The individual proposals are highly interconnected and, in aggregate, represent a wholesale change to
equity market structure at or greater than the changes made through Reg NMS which was adopted by the Commission in June 2005. Given the dramatic changes in market structure under the Reg NMS regime and technological advancements in the past two decades, we appreciate the Commission’s actions in reviewing the current state and in promulgating the Proposals. Like Reg NMS, the Proposals seek to
modernize the rules that govern U.S. markets to make them more efficient, competitive, and fair. STA
supports these goals; however, we have major concerns with several components within the Proposals
and the process under which the Commission drafted them.