A few weeks ago I investigated the currency markets and their role in our global system. They’re not well known or understood. Neither are the commodities markets. This is one of the more complicated things I’ve tried to write about, so if anyone gets these things more than I do and spots a mistake, please set me straight.There have always been commodity markets of one kind or another, such as the corn exchanges that feature in every English town. They are the meeting places where people trade c