I have a kind of "nemesis" in the City - a hotshot trader who started off on the same graduate scheme that I did. Colleagues used to think - mistakenly - that those lecherous glances we shot each other were sexual in nature, but they were actually the vitriolic expressions of our intense rivalry. And although we've parted ways since our hotly competitive beginnings, we've kept our radar finely tuned into which one of us is ahead in the City race.

And until last week, he's held the lead by a thin margin - then, incredibly, he made a series of bad decisions that lost £2 million for his bank. It was enough to get him fired for gross misconduct – and he’s checked into a clinic for physical and mental exhaustion.

When I phoned him after, he said he felt like he couldn't think clearly or control his emotions – which wasn't that surprising as he always had a bit of a temper, but could normally control it when he had a position. Not this time.

But after seeing my friend’s tragedy, I had doubts as to whether anyone with any depth of feeling could last as a trader for any extended period of time.

Working as a trader essentially involves digesting huge amounts of market information from Bloomberg, technical analyses, charts, graphs, etc. then making split-second decisions based on this information. There are dozens of rules to remember – cutting your losses, going with the trend, not picking tops or bottoms – but most importantly, never let your emotions get the better of you.

This last rule is the hardest of all to follow because most people are very emotional when it comes to money. But we’re paid huge amounts of money to ignore these feelings.

The best traders stop trading to clear their heads but, when you’re in the heat of the moment, it’s incredibly difficult to do.

Of course, the best traders are not empty, emotionless robots, but they just know how to control their feelings better than most of us.

They say “trading is man’s game,” but I don’t believe the hype. Everyone knows that women are more intuitive, and not as egotistical, aggressive or power-hungry as men. What this means for City Girls is that they tend to be more consistent traders, who don't rack up huge losses. How many 'rogue' or disgraced traders do you know who are women? Zero.

My nemesis wanted to be RIGHT, more so than he desired to be profitable.

I've always liked gambling, and strangely enough, the markets are a mixture of the heart and mind, the logical and emotional. I always thought that seeing my arch rival lose would be the highlight of my career.

But his failure doesn't give me the adrenaline rush I thought it would. Instead, it just makes me realize the fragility of my own position.