Here’s an interesting little thing. In fast moving markets, it seems to be those with the most testosterone who actually make the money from trading.

Money doesn’t make the world go round: it’s testosterone. The more that traders have, the richer they’ll become - up to a point.

John Coates, who used to manage a trading floor at Deutsche Bank on Wall Street but is now at the Judge Business School at Cambridge University, and Professor Joe Herbert, a neuroscientist, set out to study the brains of City traders to discover what makes them tick.

They measured levels of testosterone and cortisol (a stress hormone) in 17 traders at a City of London bank for eight consecutive business days. They found that those traders with higher testosterone levels in the morning were most likely to make money on the day’s trading. One trader hit a six-day “winning streak” during which he made more than double his daily profit. During that time his testosterone levels went up 74%.

Now no, this isn’t an unalloyed good: too much testosterone leads to too much risk taking and that’s a great way to lose money in markets. There’s also the point made that it isn’t just a higher starting point of testosterone levels that causes it. There’s also a feedback, in that success increases those levels.

However, as far as we are interested here, it tells us something useful about employment in the financial industry. While overall it may indeed be an equal opportunities world, it might not be in every nook and cranny of it. If surging testosterone levels are what lead to trading success (as opposed to purely being results of it) then we might find that women don’t get an even break here, for biological rather than merely societal reasons.