What’s the role of trade-through prohibitions in today’s electronic marketplace? To the bottom-line question of what to do with Rule 611, Chris Nagy, Co-founder of Healthy Markets Association, was generally constructive on trade-through prohibitions, while most other panelists leaned toward scrapping the so-called order protection rule. Hubert De Jesus, Global Head of Market Structure and Electronic Trading at BlackRock, said Reg NMS, including Rule 611, has been instrumental in integrating independent marketplaces into a cohesive market structure, and U.S. equity markets functions well. Regarding Rule 611, De Jesus noted the trade-through prohibition is closely connected to other regulations, and scrapping it by itself would be like removing the keystone from an arch. MEMX CEO Jonathan Kellner said the SEC needs to review ancillary rules and broader market structure with any changes to Rule 611, with an emphasis on strengthening displayed liquidity.