HBM Memory: SK hynix, Samsung, Micron — 2026-09-25

Top developments

Samsung HBM4 yield enters the "golden yield" zone at ~80%

Korean financial media report that Samsung's HBM4 mass-production yields, which started below 60%, have stabilized around 80% — boosting the company's confidence to expand supply aggressively. Samsung expects Q3 HBM4 revenue to more than triple from the previous quarter, with HBM4-related revenue having already topped $1 billion roughly three months after mass-production shipments began in February. SK hynix is still forecast to defend approximately 70% of Nvidia's HBM4 volume, but the market view is turning increasingly calm on Samsung's prospects.

SK hynix holds ~50% HBM revenue share as Samsung climbs to 33%

Per a Motley Fool-cited market survey reported by Global Economic on September 23, SK hynix secured a 50% HBM revenue share, with Samsung's share rising sharply — the gap narrowing from 37 percentage points to 17 points (33% vs. 50%). The competition from Micron and China's CXMT is adding pressure on both Korean leaders. Maintaining this leadership through HBM4 qualification cycles is critical as Samsung's gains erode SK hynix's pricing dominance.

Micron eyes $50B fiscal Q4 revenue ahead of September 30 earnings

Micron reports fiscal 2026 fourth-quarter results on September 30 (after market close), with expectations that quarterly revenue will top $50 billion. Analysts are focusing on HBM revenue details, long-term supply contract disclosures, and 12-layer HBM4 ramp progress — the ramp is reportedly twice as fast as 12-layer HBM3E, with cumulative HBM4 shipment revenue already above $1 billion. The print will signal whether Micron's capacity-doubling strategy is closing the gap or risking oversupply.

Samsung and SK hynix accelerate HBM production; Samsung weighs 4nm for HBM4 base dies

Samsung plans to raise average monthly HBM wafer input from roughly 180,000 units this year to about 250,000, per Sammy Fans on September 22. Separately, Money Today reported Samsung is evaluating an expansion of its 4nm foundry process to meet rising HBM4 base-die chip demand. The expansion underscores how advanced-node base-die capacity is becoming a bottleneck for HBM4 supply.

Huang's "2x chips in 2027" pledge locks up HBM supply

Jensen Huang said Nvidia intends to sell twice as many chips next year as this year, a signal that has lifted expectations for Samsung's and SK hynix's HBM and DRAM volumes. Analysis based on CNBC and Morgan Stanley data suggests the vow effectively commits as much as 37% of projected HBM supply to Nvidia, tightening availability for AMD and hyperscaler buyers. This demand surge underpins the DRAM contract price momentum suppliers currently enjoy.

Local view

Seoul Economic Daily's video briefing highlights that Samsung's HBM4 "golden yield" stabilization at ~80% is viewed as directly linked to earnings improvement and supply-expansion confidence, while noting the HBM gap with SK hynix narrowing from 37 to 17 percentage points. Kiwoom Securities cut its Q3 Samsung Electronics operating profit estimate below consensus on a weakening won and slowing commodity DRAM price gains, but maintained a Buy rating, telling investors to focus on HBM and foundry growth over generic memory. Seoul Shinmun reported that HBM average export unit price fell 3.6% in August after surging March–July — read as a supply-expansion signal as Micron and CXMT press Korean suppliers. Herald经济 previewed the memory Big 3's post-Chuseok scorecards, spotlighting Micron's September 30 earnings and HBM long-term contract disclosures.

Context & numbers

• Q2 2026 HBM revenue share: SK hynix ~50% (down 8pp QoQ), Samsung 33% (up from 21% a year ago and 21% prior quarter) — a combined ~74 trillion won HBM market at stake.
• Samsung HBM4 revenue: over $1 billion (~1.4 trillion won) within three months of February mass-production shipments; Q3 HBM4 revenue expected to more than triple QoQ.
• Micron: cumulative HBM4 shipment revenue exceeded $1 billion; 12-layer HBM4 ramp roughly 2x faster than HBM3E; fiscal Q4 (Sept 30) revenue expected above $50 billion (~68.3 trillion won).
• HBM average export unit price fell 3.6% in August 2026 after five months of gains.
• TrendForce forecasts HBM contract prices to surge multiples higher in 2027 as tight DRAM supply gives suppliers greater pricing power.

On the radar

• Micron fiscal Q4 earnings, September 30 (after close, US Eastern) — watch HBM revenue mix, long-term supply agreement disclosures, and guidance for the Vera Rubin ramp.
• Korea's Big 3 earnings season kicks off after Chuseok, with Samsung and SK hynix results to clarify HBM4 shipment pacing and Q4 pricing.
• Rumored: SK hynix–Intel US memory manufacturing talks (TechCrunch, Sept 16) remain worth tracking for any confirmation.
• Rumored: Chinese CXMT IPO (reported ~6 trillion won raise) with HBM line ramp; Korean analysts estimate a 2–3 generation technology gap, but watch for pricing pressure at the low end.