The NAND Cycle — Storage for the AI Data Explosion
AI doesn't just need fast memory next to the GPU. It needs petabytes of fast storage somewhere nearby. NAND prices are up 246% in 12 months and the cycle has just turned.
Every AI training job needs to read terabytes of data and write checkpoints every few hours. Every AI inference cluster needs to keep model weights, embeddings, and KV caches close at hand. That's all NAND flash . The category has historically been brutally cyclical (boom-bust-boom), but the combination of AI inference workloads and hyperscaler design wins for QLC flash arrays has driven a vertical price move. Per Kingston's Datacenter SSD Business Manager to TrendForce (December 17, 2025): "NAND prices — already up 246% since Q1 2025 — are likely to climb further." November 2025 contract prices for 512Gb TLC wafers rose over 65% month-over-month. The cycle is early.
NAND has the same supply structure as DRAM — a handful of giants (Samsung, SK Hynix, Kioxia, Micron, Sandisk) with multi-year cycle times to add capacity. When AI inference demand stacks on top of normal datacenter demand, prices move violently.
5 names on the watchlist
Pure-play NAND post-WDC spin. Stock +3,800% in 1 year as the NAND supercycle reasserted itself.
The NAND-only entity spun off from Western Digital in early 2025. Owns the BiCS NAND technology and the Yokkaichi/Kitakami fabs (jointly with Kioxia). Q3 FY26 revenue $5.95B with 78% gross margin (+251% YoY). The single best example in this entire document of what happens when a supply-constrained commodity meets an AI demand surge.
Japanese NAND maker. IPO'd Dec 2024 at ¥1,440; hit ¥66,090 ATH in May 2026 — roughly 43x in 17 months.
The Japanese NAND maker spun out of Toshiba . Jointly operates Yokkaichi and Kitakami fabs with Sandisk. IPO'd December 18, 2024 at ¥1,440 → hit ¥66,090 ATH on May 14, 2026 — roughly 43x. NAND prices surged 246% from Q1 2025 through December 2025. Supply sold out through 2026. AI inference QLC demand exploding. FY2026 revenue ¥2.34T (+37% YoY); US ADR listing planned.
Post-Sandisk spin, the pure-play HDD survivor — still relevant for AI cold storage. Up +900% YoY.
Post-spin, WDC is pure-play hard disk drives — the cheap, slow storage AI training and inference clusters use for archival, cold data, and large dataset staging. HDDs are still ~10x cheaper per terabyte than NAND. HDD AI capacity is sold out. HAMR (heat-assisted magnetic recording) ramp adds capacity. The "AI archive" thesis is real and AWS, Microsoft, Google are all bidding for capacity.
Dominant client SSD controller maker. PCIe SSD shipments +280% YoY in October 2025.
Taiwanese maker of SSD controllers (the tiny chip inside every SSD that orchestrates reads and writes). Over 20% global share, over 40% in automotive-grade. PCIe SSD shipments +280% YoY October 2025; sold out through 2026. Stock more than doubled in 6 months. Q4 2025 record EPS NT$21.74.
Largest merchant SSD controller — Q1 2026 revenue $342M (+105% YoY). The "Phison of the US-listed world."
Makes NAND controllers for client and enterprise SSDs . The largest merchant SSD controller maker — the way to play the NAND cycle without taking direct memory-maker exposure. Q1 2026 revenue $342M (+105% YoY); Q2 guide $393-411M. Risk: Kioxia and other customers in-housing controllers over time.
- Bernstein, TrendForce, Counterpoint · May 2026