In May 2026, SK Hynix shares surged over 15% in a single session, touching an intraday all-time high of KRW 1,949,000. Market cap briefly cleared USD 900 billion. SK Securities raised its target price to KRW 3,000,000. What drove all this? Here's a full breakdown of the key stories that defined SK Hynix's May.
1. Key Concepts
1-1. The Big Tech Investment Proposals
The dominant story of early May was a report that Microsoft, Google, and Amazon were preparing to propose direct investment in SK Hynix — offering to fund capacity expansion in exchange for securing multi-year HBM production allocations in advance.
Why would tech giants show up with money in hand? Because the HBM supply gap is running at roughly 40%, and memory supply growth cannot keep pace with AI-driven demand. This imbalance is expected to persist through 2028. For hyperscalers that need HBM to build out their data centers, a supply bottleneck directly constrains their core business — making proactive investment in the supplier a rational hedge.
1-2. HBM4 Mass Production Ramps Up
SK Hynix's sixth-generation HBM4 moved into full mass production during Q2 2026 — the key memory component for NVIDIA's next-generation "Rubin" AI accelerator. Even more notable: the company announced it would begin producing HBM4E (7th generation) within 2026, a full year ahead of the original schedule.
Manufacturing infrastructure is expanding in parallel. The Cheongju M15X fab is set to come online this year, and the first phase of the Yongin Cluster fab is scheduled for completion in late 2027, providing the production capacity backbone for HBM4 and HBM5.
1-3. New Price Highs and Target Price Upgrades
SK Hynix shares set a closing record of KRW 1,654,000 on May 7, followed by an intraday peak of KRW 1,949,000 on May 11. SK Securities upgraded its target price from KRW 2,000,000 to KRW 3,000,000, with analyst Han Dong-hee stating that "the memory re-rating cycle is still in its very early stages." Nomura Securities also raised its operating profit estimates and reaffirmed SK Hynix as its top pick in global AI-related equities.
2. Wild Card: Samsung's Comeback, How Far Along?
Throughout May, Samsung's accelerating push into HBM4 remained a central market debate. Samsung began HBM4 mass-production shipments in February 2026 — the first in the industry — and secured AMD as a significant new customer, giving it an independent demand channel outside NVIDIA. Samsung's HBM market share has climbed to an estimated 30% in Q1 2026.
That said, the industry reads the situation cautiously. The technical challenge of thinning wafers from 50μm to 30μm for 16-layer HBM4 stacking makes consistent yield difficult to achieve. The prevailing view is that "yield consistency and delivery reliability in mass production — not spec comparisons — will ultimately determine market share." Whether Samsung extends its HBM4 gains into Q4 2026 is the question to watch.
3. Wild Card: Supply Shortage as Catalyst — and Future Constraint
The current HBM shortage is unambiguously positive for SK Hynix today. With demand outpacing supply, pricing power sits firmly with suppliers — hence the unprecedented spectacle of hyperscalers offering to co-invest in capacity.
But shortages don't last forever. SK Hynix itself is aggressively expanding via Cheongju M15X and the Yongin cluster, and Samsung and Micron are doing the same. How pricing and margins behave when significant new capacity comes online in 2027–2028 will be the next major test for the thesis.
4. Bottom Line
May 2026 delivered three simultaneous catalysts for SK Hynix: a new share price record, Big Tech proposing direct investment, and HBM4 entering full production. The company's dominant position — roughly 70% of NVIDIA's HBM volume, deep partnerships with Google and Microsoft, and a technology roadmap extended to HBM4E ahead of schedule — sustains a compelling long-term narrative beyond the near-term momentum.
That said, a KRW 3,000,000 price target already prices in a great deal of optimism. Samsung's pace of HBM4 yield improvement, the HBM4E production ramp timeline, and the pricing environment when 2027–2028 capacity additions materialize are the variables worth tracking for the next phase of this story.
The structural case for AI infrastructure investment remains intact. As always, position sizing and entry timing are best decided within your own framework.