On 3 November 2014 Ethical Markets Media and the UNEP Inquiry convened an expert seminar in New York, bringing together securities market experts and traders to examine how the issues of electronic markets and high-frequency trading relate to the broader efficiency, effectiveness and resilience of financial markets in the face of environmental and social challenges, and to consider the potential of several market-based reforms. This paper documents the proceedings of this expert seminar, chaired by Ethical Market’s Media founder, president and editor-in-chief, futurist and author Hazel Henderson.