High frequency trading (HFT) is a catch-all term for the use of computer technology to trade stocks, options, foreign exchange contracts, and other financial instruments at the fastest possible speeds. HFT burst into public consciousness in 2014 with the publication of Michael Lewis’s best-selling book Flash Boys. Lewis profiled trader Brad Katsuyama’s quest to understand his difficulties in trading equities in the early 2000s. Specifically, he was unable to fill orders at the prices quoted on various markets—as soon as he sent one order, quotes on other markets would be withdrawn, only to be replaced by less attractive ones. This difficulty led him to investigate the mechanics and trading practices in contemporary markets. While critics claim that Lewis’s characterization of the stock markets as “rigged” ...