This is a result of the way we define a trader’s prowess, namely by his “Sharpe ratio,” which is calculated as the profits he generates divided by the risks in his portfolio. This ratio is crucial to a trader’s career, his annual bonus, his very sense of being. If you disembody those traders and consider them as a set of algorithms, those algorithms are relentlessly focused on optimizing the Sharpe ratio. Ideally, it will climb, or at least never fall too low.
