The researchers suspect that testosterone may increase a trader's confidence and willingness to take risks. However, too much testosterone could be dangerous. Previous studies have shown that testosterone injections can cause men to make irrational decisions.
The researchers also measured levels of cortisol, a hormone that is released in response to stress. The traders experienced spikes of cortisol during times of high volatility in the markets.
Measuring steroid hormones such as testosterone and cortisol may offer a way to predict how well a trader will perform on the job, says Professor Joe Herbert of the Cambridge Centre for Brain Repair. He and his colleagues are now exploring this in more detail.