Today's securities markets are evolving at the fastest pace ever, forcing significant changes on the investment management institutions that use them on an all‐day/everyday basis. The impetus driving toward the new market structures is primarily attributable to technological change, midwifed by regulator dictates. As has happened in so many other industries, major functions formerly operated by ‘‘carbon‐based’’ (people‐centric) systems are being taken over by ‘‘silicon‐based’’ systems of heavy computing power and advanced communications, leading to speeds faster than the human eye or brain can follow. In the process, familiar landmarks of market structure are virtually obliterated, or transmogrified into something barely recognizable. This chapter considers all the changes in securities markets and suggests that transactional basis points will always impact performance.