For the past two decades, the Securities and Exchange Commission has overseen exchanges by inspecting them occasionally and urging them, voluntarily, to examine themselves, file annual reports, and notify the agency of planned technology changes and significant system outages. (Illustration by Rami Niemi | Op-Ed by David L. Kornblau)

For the past two decades, the Securities and Exchange Commission has overseen exchanges by inspecting them occasionally and urging them, voluntarily, to examine themselves, file annual reports, and notify the agency of planned technology changes and significant system outages. (Illustration by Rami Niemi | Op-Ed by David L. Kornblau)