Algorithmic and high frequency trading use computer algorithms to execute strategies and the confluence of trends in computer hardware, programming, mathematical modelling, and financial innovation have pushed the limits of trading speed to unprecedented levels. Algorithms are fast and automatically spread disruptions through the financial system. Over the last decade, the ensuing systemic risk called for new regulations. This article attempts an early assessment of the new European legal framework (Mifid 2 and Market Abuse Regime) intended to tackle the technological risks of the modern trading paradigm.