Resumen de Editorial: : When finance becomes science.

• The editor shares insight on the implementation of the Markets in Financial Instruments Directive II (Mifid II) by (Esma). The editor notes the struggle of Esma to regulate high-frequency trading (HFT). Three things are suggested for the regulation of HFT, which are understanding of HFT's nuances and physical characteristics, knowledge of the ways traders manipulate the market, and the means to ensure fairness in the market.