Two Roads Out of the Memory Boom: Samsung and SK Hynix Choose Differently
Korea’s two memory leaders reached a fork in late June 2026 — Samsung pressing its HBM4 advantage, SK Hynix retreating toward DDR5 margins.
TL;DR — South Korea’s memory giants have split on strategy: Samsung is racing to ramp HBM4 (sales reportedly topping $1B), while SK Hynix is slowing its HBM4 conversion to harvest ~90%-margin DDR5 — a divergence that rattled chip stocks in late June 2026.
Samsung and SK Hynix have spent years racing down the same road. In late June 2026, they reached a fork — and turned in opposite directions.
The split
Reports around June 22–24, 2026 (TrendForce, DigiTimes) describe a strategic divergence between the two Korean memory leaders:
| Samsung | SK Hynix | |
|---|---|---|
| HBM4 stance | Ramping aggressively | Slowing the ramp |
| Reported HBM4 sales | Topped $1B (projected ~$1.2B by end-June) | (pulling capacity back) |
| 2026 HBM shipment revision | Revised up (to ~4B Gb) | Revised down (4.5B → ~4B Gb) |
| The pivot | Push HBM4 share | Retool some lines for DDR5 |
| Why | Win the AI-memory socket | DDR5 margins approaching ~90% |
SK Hynix’s logic is margin: with conventional DDR5 operating margins reported near 90%, HBM already more than 40% of its revenue, and its 2026 HBM supply sold out, it is in no hurry to convert additional lines to HBM4. Samsung, by contrast, is pressing its HBM4 advantage to claw back share. The news landed amid a volatile stretch for chip stocks worldwide.
What they said
"[Strong first-quarter results] reveal that a lot more memory is needed for AI inference than expected, with companies rushing to secure supply." — MS Hwang, Research Analyst, Counterpoint Research
Why it matters
- HBM4 is the prize socket of the AI era. Who supplies it — and how fast — shapes the entire accelerator supply chain.
- Margins can beat market share. SK Hynix is betting that ~90%-margin DDR5 is worth more than racing on HBM4 volume.
- Supply is the swing factor. Small shifts in Korean HBM plans ripple through Nvidia, the cloud builders, and memory pricing worldwide.
FAQ
How are Samsung and SK Hynix diverging on HBM4?
Per TrendForce and DigiTimes reporting in late June 2026, Samsung is ramping HBM4 aggressively — with sales reportedly topping $1 billion — while SK Hynix is slowing its HBM4 conversion and retooling some lines for DDR5, whose operating margins are reported near 90%.
Why would SK Hynix slow down HBM4?
Margins. Conventional DDR5 operating margins are reported approaching 90%, HBM is already over 40% of SK Hynix’s revenue, and its 2026 HBM supply is sold out — so it can prioritize the most profitable mix rather than convert every line to HBM4.
Sources
Image: “SK Hynix DDR5 Tall MRDIMM” by 4300streetcar, CC BY 4.0, via Wikimedia Commons.
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