Tying automated trading to “sentiment analysis”—so that trading programs buy when a stock becomes a meme or sell when bad news goes viral—can make pump-and-dumps and smear campaigns much more profitable. But the most virulent of all modern exchange hacks is high-frequency trading, or HFT. Instead of making use of true, albeit secret, information or disseminating disinformation, HFT exploits public information at lightning speed.
