Huang's remarks crystallized a hierarchy that Wall Street is now pricing in aggressively. "We should use copper as much as we can, for as long as we can, but copper has its limits," he said. "The right strategy is to scale up with copper as long as you can — after that you scale up further with optics, you scale out with optics and you scale across with optics. So you use optics wherever you must, you use copper wherever you can."