HBM4 ramp-up and AI server memory upgrades drive SK Hynix's earnings and valuation re-rating

Overview

This is Citi's company research and rating revision report on SK Hynix. The core view is that AI server demand, HBM4 ramp-up, stronger-than-expected HBM3e demand, and rising server DDR5 and SSD prices will together drive a significant upward revision to SK Hynix's earnings from 2026 to 2027.

Core views

Citi believes SK Hynix has DRAM technology leadership, high exposure to server applications, and a leading HBM position, allowing it to capture greater earnings leverage during the storage industry upcycle. The report specifically highlights that higher token limits in AI applications such as Anthropic may further amplify inference-side memory and storage demand, thereby supporting continued strength in commodity memory prices.

Analysis framework

The report is structured around three layers: product price assumptions, segment-level earnings forecasts, and valuation multiples. It first raises ASP forecasts for DRAM, NAND, HBM, server DDR5, and SSDs, then lifts operating profit and net profit forecasts accordingly, and finally estimates the value of the HBM business and the commodity storage business separately through an SOTP framework.

Methodology notes

• Valuation methodsSOTP sum-of-the-parts valuation

  Separates SK Hynix's operating businesses into HBM and commodity/other storage businesses for valuation.

  The HBM business is valued using logic closer to customized and customer-specific markets, while the commodity storage business is valued using forward EV/EBITDA multiples typical of the early or rising phase of the storage industry.

• Earnings forecastASP scenario forecasting

  Derives revenue and profit from price assumptions for DRAM, NAND, HBM, server DDR5, and SSDs.

  The report raises its 2026E server DDR5 and SSD ASP growth assumptions and expects HBM to rise 30% QoQ in Q4 2026.

• Investment ratingExpected total return framework

  Citi's Buy rating is based on expected total return over the next 12 months.

  The report states that Citi's Buy rating typically corresponds to an expected total return of 15% or more over the next 12 months, and 25% or more for high-risk stocks.

Asset mapping & comparison

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

• SK Hynix 000660.KS

  Core coverage name

  Strengths

  HBM leadership, DRAM technology leadership, high exposure to server applications, and benefits from AI inference and data center demand.

  Weaknesses

  Still exposed to storage cycle volatility, weak mobile demand, and downside risk from NAND demand coming in below expectations.

  Comparison

  The report references valuation logic from high-quality semiconductor peers such as TSMC when valuing the HBM business, while valuing the commodity storage business at multiples typical of an industry upcycle.

  Risks

  A decline in DRAM demand, NAND demand below expectations, weak global consumption, or an unexpected end to the storage upcycle.

• TSMC

  Valuation reference and industry benchmark

  Strengths

  Leadership in advanced process technology, strong AI demand, and a firmly established foundry leadership position.

  Weaknesses

  May be affected by depreciation costs, Taiwan dollar appreciation, competitors entering foundry business, and prolonged inventory digestion.

  Comparison

  The report uses TSMC as one of the references for the fair value multiple of the HBM business, because the high-end storage market is evolving toward a more customized, customer-specific model.

  Risks

  Global semiconductor weakness, margin compression, global trade disruptions, or an economic recession.

Key data

• RatingBuyMaintained Buy rating.
• Target price₩3,100,000Previously ₩1,700,000.
• Implied return83.9%The report body discloses a return of 83.9%.
• 2026E operating profitKRW 251 trillionUp 8% versus the prior forecast.
• 2027E operating profitKRW 347 trillionUp 16% versus the prior forecast.
• Q4 2026 HBM ASPQoQ +30%Driven by the HBM4 mix effect and stronger-than-expected HBM3e demand.
• 2026E server DDR5 DRAM ASPYoY +329%Previously forecast at +308%.
• 2026E SSD ASPYoY +267%Previously forecast at +242%, driven by KV cache storage demand.
• Q4 2026 server DDR5 64GB DIMM price$1,586Previously forecast at $873, mainly driven by AI inference demand.

Impact & implications

If the report's assumptions materialize, SK Hynix's earnings leverage will be significantly higher than that of a traditional storage cycle, and its valuation logic may shift from a pure commodity-cycle stock toward a semiconductor asset with more customization, customer stickiness, and AI infrastructure characteristics. For investors, the key is not a single quarter's shipments, but whether the HBM product mix, AI server memory upgrades, and commodity storage prices can form a sustained positive feedback loop.

Risks

• A decline in DRAM demand could weaken the logic behind price increases and earnings upgrades.
• NAND demand below expectations could affect SSD and storage mix benefits.
• Weak global consumption could offset part of the growth from server and AI demand.
• Loss of DRAM market share or an unexpected end to the storage upcycle could weigh on valuation.
• A weak global semiconductor market, trade tariffs, or prolonged inventory digestion in the supply chain could drag on industry demand.

What to watch

• The HBM4 ramp-up pace in 2H 2026 and the sustainability of HBM3e demand.
• Whether HBM ASP can achieve 30% QoQ growth in Q4 2026.
• Whether server DDR5 64GB DIMM prices approach the forecast of $1,586.
• Whether SSD and NAND prices continue to be supported by KV cache and AI data center storage demand.
• The transmission of AI inference demand, higher token limits, and data center capex into memory demand.
• Whether SK Hynix maintains its lead in HBM customer share, product mix, and gross margin.