Elegant Structural Solutions to Portfolio Theory

In my lifetime, there are a few ideas that structurally click — once you see them, you can’t unsee them.

One of them is why the U.S. dollar has performed the way it has over the last 25 years.

On the surface, the dollar looks range-bound.

The basket appears flat.

But that headline misses the structure.

Against major developed currencies, the dollar didn’t …