Micron broke ground this week on a roughly $9 billion HBM fab inside its existing Hiroshima campus, with first shipments targeted for the summer of 2028. Strip away the ribbon-cutting and the strategic logic is genuinely sound: HBM is the most constrained component in the AI supply chain, Micron is the number-three player trying to close the gap on SK Hynix and Samsung, and the Japanese government is covering a large slice of the bill. Every part of that is defensible. The problem isn’t the decision — it’s the arrival date. This capacity lands in 2028, which is precisely the year the supply-glut argument that drove this week’s memory selloff says the cycle rolls over. The same event is the bull’s bottleneck-reliever and the bear’s Exhibit A, and which one it becomes won’t be knowable for two years.