Man Vs. Machine: How the Crash of ’87 Gave Birth To High-Frequency Trading

A small coterie of savvy investors smelled an opportunity. Since the SOES trades were automated, meaning they received almost instant execution, and were given priority ahead of the rest of the market, a fast-moving trader could move in and out of stocks using SOES at a far-more rapid clip than large investors, generating big profits. (CNBC)