National Securities Market System Act of 1973 : hearings before the Subcommittee on Securities of the Committee on Banking, Housing and Urban Affairs, United States Senate, Ninety-third Congress, first session on S. 2519, to amend the Securities Exchange Act of 1934 to facilitate the development of a national market system, to provide for regulation of securities information processors, to remove unnecessary burdens on competition, and to strengthen and improve the Securities and Exchange Commission's oversight of self-regulatory organizations, and for other purposes, November 12, 13, and 14, 1973.