Micron's HBM Pricing Power Now Shows Up in Nvidia's Own Price Sheet: the 64GB DGX Spark Costs $1,000 More Than the 128GB Original
Update 2026-10-18: the first real stress test of the memory leg arrived this week — China's CXMT claimed "key progress" on a denser DRAM architecture and memory equities had their worst selloff of the AI era — and the HBM pricing-power leg came through untouched. The claim is a commodity-DRAM density roadmap (4F² vertical-transistor cells), not HBM: every analyst read this cycle agrees CXMT has no near-term answer to the stacked memory that sits next to Nvidia's accelerators, where SK Hynix and Samsung remain "unquestionably dominating."
Prior revision (2026-10-06): the memory leg crossed from supplier economics — Micron's sold-out HBM at 86%+ margins — into end-product pricing at Nvidia itself: the 64GB DGX Spark costs $1,000 more than the 128GB original, memory scarcity now visible on Nvidia's own price sheet.
The CXMT episode: what was claimed, and what actually broke
Over the Oct 10–11 weekend, CXMT (ChangXin Memory Technologies) announced significant progress on a new chip architecture that increases memory density by packing more data into less space — the 4F² vertical-transistor DRAM design (per CNBC, citing CLS). The equity reaction was violent: SK Hynix plunged more than 10% in Seoul and Samsung fell 7.4% (both to their lowest since August), Korea's Kospi lost 5.5%, Micron slid 3.9% then another 5.6% by Friday, and the selloff spread through SoftBank (-8.5%), Tokyo Electron (-7.2%), ASML (-3.3%), STM and Infineon (-5%).
But the fundamentals of the HBM leg did not move:
- Goldman Sachs told clients Friday the CXMT threat to advanced memory is overblown and called SK Hynix and Samsung attractive risk/reward after the selloff (247wallst).
- UBP's Vey-Sern Ling (to CNBC): "In reality, while the Chinese memory makers can potentially become a threat to global demand-supply balance over time, in the short run they continue to face technology hurdles, especially for more advanced memory like HBM."
- Rayliant's Phillip Wool (to CNBC): "More importantly, we're not even talking about HBM here, and the Korean chipmakers are still unquestionably dominating that space, with very little threat at all from the likes of CXMT or anyone else for the foreseeable future." His read on the selloff itself: "I read that more as a sign of how vulnerable AI sentiment is at this moment."
- SemiAnalysis (via SCMP) estimates CXMT's cost per bit of DDR5 remains more than 30% higher than its three largest rivals, and HBM contributes little to its revenue. CXMT is fourth in DRAM: Samsung 39.4%, SK Hynix 24.9%, Micron 23.3% (Korea Herald).
- The incumbents are already on the same roadmap: Samsung has demonstrated a working 16Gb 4F² DRAM prototype, and Samsung Device Solutions CTO Song Jai-hyuk answered simply "Yes" when asked at a Seoul exhibition whether Samsung is developing 4F² (Korea Herald).
- Musk amplified the long-run fear on X: "When China figures out how to manufacture a product, their ability to scale is often greater than the rest of the world combined."
What it means for the capex story
The HBM sold-out/86%-margin pricing-power leg — and therefore the memory-cost input to Nvidia's gross-margin track (watch: gross_margin <= 72, guided ~74.0% for Q3 FY2027) — is unchanged by CXMT's claim. The episode is a sentiment amplifier, not a supply-curve shift: it demonstrated how little bearish catalyst the tape needs ("how vulnerable AI sentiment is at this moment"), which matters for the equity leg of Nvidia's AI Capex Cycle Sustainability: Verdict 2026-10-18 — Intact for a Nineteenth Straight Read; Huang Goes Public With "All of This Is Going to Pass" as NVDA Trades as the Group's Safe Harbor but not for the demand or margin legs. The genuine long-run risk (CXMT scaling commodity DRAM and pressuring the incumbents' conventional-DRAM cash flows, per Musk's scaling point and the 206% ASP forecast) is a 2027+ story that doesn't touch HBM4/HBM4E allocation for Nvidia's stack this cycle.