How would you like to make $1,287 in 10 minutes? Well, if you had purchased a $100,000 lot of U.S. dollar/Japanese yen on Dec. 10, 2003, at 107.40 and sold 10 minutes later at 108.80, you could have. It would have worked like this:
1. Bought $100,000 and sold 10,740,000 yen (100,000*107.40)
2. Ten minutes later, the USD/JPY increases to 108.80
3. Sell $100,000 to buy 10,880,000 yen, to realize a gain of 140,000 yen
4. In dollar terms, the gain would be 140,000/108.8 = $1,286.76 USD
So, who was on the other end of the trade taking the huge losses? Believe it or not, it was the central Bank of Japan. Why would they do this? The act is known as an intervention, but before we discover why they do it, let's quickly review the economics of...