In one experiment, for example, Coates studied the testosterone levels of a group of traders at a high-frequency London trading shop. He found that their testosterone was significantly higher following days when they’d made an above-average profit. But the converse was also true. Coates had also been checking their testosterone in the morning and discovered that they had substantially better trading days when they woke up with higher T levels. Higher testosterone predicted more trading success, in other words. More testosterone, more profit. What could possibly go wrong?
