What do traders do? They make investments on behalf of their employers, the banks, and the banks' customers. They watch screens all day, looking for fluctuations in prices, and then try to buy things when they are cheap and sell them when they are expensive. So what they are really trading in is opinions. They are like bookies once removed; they make bets on how other people will bet. Traders, in other words, are pure capitalists; they understand that something is worth exactly what people say it's worth.
A rogue trader is not a crook in the normal sense of the word. He is someone who lose…
