SanDisk is the reference point that started this. After spinning out of Western Digital in early 2025, the stock bottomed near forty dollars in April of that year and now trades close to nineteen hundred — a forty-five-fold move accomplished in roughly twelve months. It is the kind of chart that sends investors hunting for the next one. But the lesson of SanDisk is easy to misread. It did not climb because of a proprietary technology nobody else had. It climbed because NAND flash entered a brutal undersupply, pricing inflected, and a newly independent company captured the entire swing. That is a commodity supercycle, not a moat. Memory re-rated because the physics of supply and demand turned, and the same mechanism will eventually turn the other way.