(FLASH FRIDAY is a weekly content series looking at the past, present and future of capital markets trading and technology. Katie Kolchin, head of equity and options market structure at industry body SIFMA, detailed on the panel how markets have changed in the last two decades. She said one of the original objectives for Reg NMS was to correct market inefficiencies and create the national automated, connected market system. Its arms can even continue to move after death.”She used the analogy that like the octopus, market structure involves many moving interconnected pieces, and Rule 611 represents the head of this octopus. The complexity of octopus biology seems like an apt analogy for the complexity of U.S. market structure for equities and options.