Regulatory reforms to improve equity market structure : hearing before the Subcommittee on Securities, Insurance, and Investment of the Committee on Banking, Housing, and Urban Affairs, United States Senate, One Hundred Fourteenth Congress, second session, on examining recent efforts by the SEC and FINRA in aiding the functioning and stability of the equity markets, and identifying key issues under consideration to reduce market complexity, increase operational stability, and promote efficiency, competition, and capital formation, March 3, 2016