You're young and want to get ahead. You work weekends and message colleagues with inspired trading ideas at all hours. You've just marked yourself as a potential rogue trader. Welcome to the brave new world of trader surveillance, where former Goldman Sachs research analyst Erkin Adylov is building a library of banking villainy based on the behaviors of hundreds of past miscreants such as UBS Group's Tom Hayes and Societe Generale's Jerome Kerviel. Using thousands of inputs, from stress levels in voice recordings to the frequency of visits to the staff canteen, Adylov and his team at startup Behavox grade employees on how likely they are to go bad before they do anything wrong. While that may sound like something out of a Philip K. Dick science-fiction novel, hedge fund Marshall Wace and interdealer broker TP ICAP are already using the software to monitor employees, and some of the biggest investment banks and commodities dealers in the world have begun testing it.

The trader was in deep trouble. A millennial who had only recently been allowed to set foot on a Wall Street floor, he made bad bets, and in a panic to recoup his losses, he'd blown through risk limits, losing 4.9 million in a single afternoon. The trader was taking part in a simulation run by Andrew Lo, an MIT finance professor. The goal: find out if top performers can be identified based on how they respond to market volatility. Lo had been invited into the New York-based global investment bank--he wouldn't say which one--after giving a talk to its executives.