South Korea’s HBM Exports Hit New High in May, Samsung Shows HBM4 Ramp-Up Signals

Overview

Bernstein has released its May tracking report on South Korean memory exports. The data show that HBM-related exports hit a record high in May, indicating robust quarter-over-quarter growth in HBM revenues for Samsung and SK Hynix in Q2’26. Additionally, structural shifts in Samsung’s export data suggest early signs of an HBM4 ramp-up. The firm maintains an “Outperform” rating for Samsung, SK Hynix, and Micron, but holds a structurally negative view of KIOXIA.

Core views

Record-high HBM exports in May point to strong Q2 revenue expectations: South Korea’s exports of multi-chip memory to Taiwan and Malaysia increased 13% month-over-month to $4.2 billion, setting a new record. Regression models forecast Samsung’s Q2 HBM revenue up 58% quarter-over-quarter to $5.6 billion, while SK Hynix is expected to see a 25% increase to $7.5 billion. Although Samsung’s figures fell slightly short of the firm’s earlier projections—likely due to delays in NVIDIA’s Rubin architecture—the overall growth momentum remains solid. Early HBM4 ramp-up signals from Samsung: By tracking the “per-unit export value” metric, the firm found that Samsung’s (Chungcheongnam-do) figure surged 30% month-over-month, while SK Hynix’s remained steady. Given that HBM prices have not risen across the board, this jump primarily reflects the accelerated shipment of Samsung’s high-value HBM4 products. The firm expects Samsung’s HBM market share to gain further traction as HBM4 ramps up in the second half of the year. HBM prices immune to traditional memory price volatility: Over the past two quarters, traditional memory prices have risen rapidly, yet HBM prices have remained largely stable. The firm believes that current supplier-customer negotiations over 2027 HBM contracts and pricing could lead to upward revisions in 2027 earnings forecasts and provide near-term support for memory stocks. Traditional memory price hikes continue, with diverging stock ratings: The ongoing rise in traditional memory prices will continue to bolster related stocks in the second half of 2026. The firm takes a structurally bullish stance on Samsung, SK Hynix, and Micron, but remains wary of potential NAND threats from Chinese competitors and views KIOXIA’s valuation as overpriced, maintaining an “Underperform” rating.

Analysis framework

The firm’s analysis follows a three-step framework: “High-frequency customs data → Company quarterly revenue forecasting → Product mix and pricing decomposition.” First, it focuses on specific South Korean provinces housing Samsung and SK Hynix’s HBM packaging and wafer fabrication facilities (Chungcheongnam-do, Chungcheongbuk-do, and Icheon City), using their exports to Taiwan and Malaysia—major HBM packaging and consumption hubs—as proxies for HBM revenue, then builds regression models to project quarterly results. Second, it introduces the “per-unit export value” metric, leveraging HBM’s heavier and more expensive nature compared to traditional memory to isolate the impact of HBM4 and other next-generation products, rather than attributing changes solely to price increases in legacy offerings.

Methodology notes

• Industry/Industrial Analysis FrameworkUpstream–Midstream–Downstream Transmission

  Using regional customs export data as a proxy for downstream company earnings

  Due to the lag in earnings reports, the firm tracks memory exports from Samsung and SK Hynix’s manufacturing hubs (e.g., Chungcheongnam-do, Chungcheongbuk-do) to specific destinations (Taiwan, Malaysia) to build regression models forecasting HBM revenue for the quarter, helping investors anticipate fundamental turning points.

• Industry/Industrial Analysis FrameworkVolume-price decomposition

  Decomposing price changes and product mix upgrades via “per-unit export value”

  HBM has a higher per-unit weight and value than traditional memory. When traditional memory prices rise but HBM prices remain stable, a sudden surge in a region’s per-unit value suggests that high-value new products (such as HBM4) are accelerating shipments, rather than just older products becoming more expensive.

Asset mapping & comparison

Structured mapping from thesis to named assets (strengths, weaknesses, peers, risks).

• Samsung Electronics (005930.KS)

  Benefit logic: HBM4 is ramping up, with market share expected to strengthen in the second half.

  Strengths

  Smooth progress on HBM4; significant improvement in per-unit value.

  Weaknesses

  Q2 export data slightly below the firm’s expectations; Rubin delay may affect short-term pacing.

  Comparison

  HBM4 ramp-up signals are clearer than those at SK Hynix.

  Risks

  Favorable pricing environment may end prematurely; competition from Chinese manufacturers.

• SK Hynix (000660.KS)

  Benefit logic: HBM exports remain steady, with strong Q2 revenue expectations.

  Strengths

  Leading HBM market share; large export base.

  Weaknesses

  Per-unit value remains flat; HBM4 ramp-up signals are not yet as pronounced as Samsung’s.

  Comparison

  Q2 revenue forecast still exceeds Samsung’s.

  Risks

  Favorable pricing environment may end prematurely; competition from Chinese manufacturers.

• Micron (MU)

  Benefit logic: Strong overall HBM demand and rising traditional memory prices.

  Risks

  Favorable pricing environment may end prematurely; competition from Chinese manufacturers.

• KIOXIA (285A.JP)

  Damage logic: Facing fierce competition from Chinese NAND players, with SOTP valuation indicating current stock price is overvalued.

  Strengths

  Short-term support from rising traditional memory prices.

  Weaknesses

  Structurally threatened by China’s NAND capacity expansion; valuation appears inflated.

  Comparison

  The firm holds a structurally negative view, assigning an Underperform rating.

  Risks

  NAND demand may grow beyond expectations; Japanese government subsidies provide support.

Key data

• South Korea’s May Exports of Multi-Chip Memory to Taiwan and MalaysiaUS$4.2 billion13% month-over-month increase, a new record high
• Projected Samsung Q2’26 HBM RevenueUS$5.6 billion58% quarter-over-quarter growth
• Projected SK Hynix Q2’26 HBM RevenueUS$7.5 billion25% quarter-over-quarter growth
• Samsung’s May Per-Unit Export Value Month-Over-Month Growth Rate+30%Reflects the accelerated shipment of HBM4

Impact & implications

The May data confirm the resilience of HBM demand; although NVIDIA’s Rubin architecture delays may slightly disrupt short-term shipment rhythms, HBM4’s early ramp-up lays the groundwork for second-half growth. The stability of HBM prices and the upcoming 2027 long-term contract negotiations could drive market expectations for future earnings revisions. Meanwhile, the traditional memory price cycle persists, keeping the industry’s overall earnings environment favorable, though vigilance is needed against medium-to-long-term structural risks posed by China’s NAND capacity and technological advances.

Risks

• Premature end of the favorable pricing environment (due to weakening demand or oversupply).
• Valuation swings caused by shifts in investor sentiment.
• Structural competitive threats from Chinese memory manufacturers, particularly in the NAND space.

What to watch

• The actual pace of Samsung and SK Hynix’s HBM4 ramp-up and volume release in the second half of 2026.
• Progress in supplier–customer negotiations over 2027 HBM contracts and pricing.
• IPO developments and NAND capacity expansions among Chinese firms (e.g., CXMT, YMTC).
• Subsequent recovery in Malaysian export data (to validate EMIB packaging demand).