HBM is sold out through 2027 and SK Hynix posted 49 percent operating margins on it. NAND is undersupplied for the first time in a decade, with KV-cache offloading and 122 TB QLC drives adding a new demand tier that didn’t exist 18 months ago. Macronix becomes the only credible sub-32GB MLC supplier in the world after Samsung exits in October 2025. This is a multi-year up-cycle, not a quarter-to-quarter print.
The 2024 to 2026 memory cycle is the first one that is not just a commodity boom and bust. HBM has decoupled from the rest of DRAM and now functions as a long-cycle, contracted, high-margin business sold to NVIDIA, AMD, and the hyperscalers under multi-year supply commitments. SK Hynix posted 49% operating margin in FY2025, an all-time record for any memory maker, almost entirely on HBM3E shipments. Simultaneously, the NAND industry is undergoing a structural consolidation as Samsung, SK Hynix, Micron, and Kioxia all exit sub-32GB MLC eMMC by 2028, leaving Macronix as the only credible global supplier. KV cache offloading is creating a new structural NAND demand tier (122 TB QLC drives at hyperscalers) that did not exist 18 months ago. Sell-side consensus and FundaAI both project shortage through 2027 to 2028, with capex commitments today not delivering wafer output until late 2027 at the earliest. This is a multi-year up-cycle, not a quarter-to-quarter print.
| Rank | Ticker | Conviction | One-Line Thesis | Biggest Risk |
|---|---|---|---|---|
| 1 | 000660.KS (SK Hynix) | High | HBM near-monopoly, 62% share, 49% FY25 op margin | HBM4 multi-vendor competition 2H 2026 |
| 2 | MU (Micron) | High | HBM share gainer, NVIDIA Vera Rubin 12-high HBM4 supplier, 56% data center | Samsung HBM4 qualification timing |
| 3 | 2337.TW (Macronix) | High | Sub-32GB MLC eMMC monopoly post-2028, 265x eMMC revenue ramp | Q1 2026 actuals must validate KGI thesis |
| 4 | 285A.T (Kioxia) | Medium-High | NAND-only purest play, 7.8x forward P/E | Bain selldown overhang ($3-4B per block sale) |
| 5 | SNDK (Sandisk) | Medium-High | Post-spin operating leverage extreme, KV cache QLC qualifying | Already +295% YTD; entry less attractive |
| 6 | 005930.KS (Samsung) | Medium | HBM3E qualification recovery, HBM4 30%+ NVIDIA allocation target | Diversified, less pure than Hynix |
| 7 | 688008.SS (Montage) | Medium | DDR5 RCD 36.8% share, IP-like high-margin | China A-share access constraint |
Avoid: Western Digital (HDD-only post-spin, no HAMR catalyst yet), Nanya Technology (no HBM, behind Winbond on tech), Powerchip (foundry+DRAM hybrid, China substitution risk).
Note: Kioxia ticker is 285A.T, not 6600.T as commonly mis-cited.
| Item | Detail |
|---|---|
| Listing | December 18, 2024 (delayed from October) |
| IPO price | ¥1,455 (midpoint of ¥1,390-1,520) |
| First-day close | ~¥1,645 (+13%) |
| Total raised | ¥120.4B (~$800M) including greenshoe |
| IPO market cap | ¥784B (~$5.2B) |
| Float at IPO | ~28% (below TSE Prime 35% requirement) |
| Bain entry (2018) | ¥2T consortium deal, Asia’s largest LBO at the time |
| SK Hynix entry (2018) | ¥395B (~$3B) for ~14% post-conversion stake |
| Date | Event |
|---|---|
| Dec 18, 2024 | IPO; 180-day lock-up begins for all major holders |
| Jun 15-16, 2025 | 180-day lock-up expires |
| Nov 25, 2025 | Bain block sale #1: ~36M shares at ~¥9,000 = ~¥355B (~$2.3B) |
| Late Feb-early Mar 2026 | Bain block sale #2: ~35-40M shares at ~¥20-25K = ~¥700-1,000B (~$3.5B) |
| 2028 | SK Hynix’s 15% voting cap on convertible bonds expires |
| 2030 (target) | Kioxia management goal: hit 35% TSE Prime float |
| Holder | At IPO | Current (est.) | Notes |
|---|---|---|---|
| Bain Capital (BCPE Pangea) | ~52% | ~28-30% | Two block sales executed; more expected |
| Toshiba / JIP | ~32% | ~27-30% | No sales yet; expected to sell down |
| SK Hynix | ~14% | ~14% | Voting capped at 15% until 2028 |
| Hoya | ~3% | ~3% | Stable |
| Free float | ~28% | ~28-35% | Rising as Bain sells |
| Metric | Value |
|---|---|
| Total realized to April 2026 | ~$5.7-5.9B |
| Remaining stake at ¥34,580 | ~163M shares = ~¥5.6T (~$37B) |
| Total position value | ~$43-44B against $18B consortium deal |
Conclusion: There is no price threshold that would cause Bain to hold. Expect another ~5% block sale (~¥480B / ~$3.2B) within 6-12 months. Position size against the supply pressure.
FundaAI is extremely bullish on MU, SNDK, and Kioxia 285A for FY2026 EPS, with implied targets ~50-100% above sell-side consensus. The structural thesis is robust (HBM permanent demand, NAND undersupply, pricing leverage non-linear, supply discipline holds, AI accelerator scarcity persists). I’d haircut the EPS bull cases by 20-30% for HBM4 multi-vendor risk and macro tail risk, and weight Sandisk and Kioxia higher than Micron given NAND has the tighter near-term shortage signal and Samsung is a bigger threat to Micron than to Hynix.
Action needed: Chrome session at funda.ai is logged out. Once logged back in, re-run the Estimate Analysis tool on MU, SNDK, 285A.T to pull live FY2026 EPS targets and validate revenue/ASP assumptions against management guidance ranges.
| Metric | What it measures | Where to find | What’s bullish |
|---|---|---|---|
| HBM bit demand growth YoY | Demand for accelerator memory | SK Hynix earnings, NVIDIA capex | >70% YoY through 2027 |
| NAND contract price QoQ | NAND cycle health | TrendForce monthly | +10% or more QoQ sustains thesis |
| DRAM contract price QoQ | DRAM cycle health | TrendForce monthly | +10% or more QoQ sustains thesis |
| TSMC CoWoS capacity | HBM packaging bottleneck | TSMC earnings | Capacity expansion lags HBM demand = sustained scarcity |
| CXMT global DRAM share | China substitution threat | TrendForce | <10% by year-end 2026 = thesis intact |
| Macronix eMMC bit shipment | Validates KGI thesis | Macronix monthly sales | Q1 2026 print = first real test |
| Bain Kioxia next block sale | Supply pressure on 285A | TSE filings, JP press | Larger block at lower price = capitulation, buy |
| HBM4 Samsung qualification | NVIDIA premium compression risk | Samsung earnings | Delay = SK Hynix premium intact |
| Priority | Command | Why |
|---|---|---|
| 1 | Log into funda.ai in Chrome, then /funda-tools Estimate
Analysis on MU, SNDK, 285A.T |
Refresh Section 15 with live FY2026 EPS and validate vs sell-side |
| 2 | /checklist 2337.TW (Macronix) |
Pre-buy discipline before sizing eMMC monopoly thesis |
| 3 | /dcf 000660.KS (SK Hynix) |
DCF to price the HBM premium, pressure-test the 49% margin extrapolation |
| 4 | /mgmt-dd 285A.T (Kioxia) |
Standalone management quality vs Bain overhang |
| 5 | Watch Macronix Q1 2026 print | First real-world test of KGI’s eMMC ramp thesis (NT$0.86B → NT$56.4B in 2026) |
| 6 | /profile 688008.SS (Montage) |
DDR5 RCD bottleneck deep-dive — IP-like compounder, HK-Connect access |
| 7 | Watch for Bain’s third Kioxia block sale | Sets supply baseline through 2026; potential entry on capitulation |
Full primer at
~/claude/output/primer/memory-sector-primer.md (10,200
words). Built on prior vault research (data-center-memory-types.md,
nand-flash-kv-caching-llm.md, Macronix KGI translation), four parallel
research threads (memory physics, company financials, Kioxia IPO
structure, earnings transcripts last 8 quarters), and SemiAnalysis /
FundaAI / KGI / TrendForce sources.