Industrial metals, such as copper (HGJ24), have outperformed stocks this year, as signs of a revival in demand from Chinese manufacturers add to concerns over tighter global supply. The much-ballyhooed forecast surplus of copper going into 2024 has suddenly disappeared. The next couple of years were supposed to be a time of plenty for copper, thanks to a series of big new projects starting up around the world. The expectation was for a comfortable surplus before the market would tighten again later this decade. But that forecast has turned out to be dead wrong. Copper and other industrial meta…