SK Hynix — HBM Leader

SK Hynix is a South Korean memory semiconductor manufacturer and the world's largest supplier of High Bandwidth Memory (HBM), the stacked DRAM that sits beside Nvidia and AMD AI accelerators and supplies the bandwidth those GPUs use to train and serve frontier models. Across 2024–2026 HBM supply became one of the tightest constraints on Nvidia GPU output, making SK Hynix's allocation decisions a factor in how fast Western frontier compute can scale.

Snapshot

HBM capacity and roadmap

Revenue and capex

Role in the AI compute supply chain

SK Hynix is the primary HBM supplier to Nvidia. It qualified HBM3 and HBM3E ahead of competitors and captured the majority of Nvidia's HBM allocation for the H100, H200, and Blackwell generations. SemiAnalysis reports that SK Hynix's 2026 HBM output is fully sold out to Nvidia, AMD, and hyperscaler ASIC customers, with allocations locked in by mid-2025, and projects capacity reaching roughly 270,000 wafers per month of HBM by 2026, up from a small fraction of that in 2023 (Source: Raw Sources/SemiAnalysis - CoWoS and HBM Supply Chain.md).

HBM supply is currently the tightest constraint on Nvidia GPU output, which positions SK Hynix as a de-facto governor of how fast Western frontier compute can scale. If HBM remains the binding constraint on AI training compute through 2026–2027, SK Hynix's allocation decisions effectively shape which labs can train the largest models.

Products and technology roadmap

SK Hynix led the industry to HBM3E (9.6+ Gbps per pin, in 8-Hi and 12-Hi stacks), with HBM3E parts shipping in 2024–2026, and is first to sample HBM4 (16-Hi stacks, wider interface) for 2026–2027 accelerators, with HBM4 volume expected in 2027. On April 22, 2026 it opened a $12.85 billion HBM4 fab, which the company framed as supporting its HBM4 position against Samsung and Micron through 2027 (Source: skhynix.com).

Beyond HBM, SK Hynix produces DDR5 and LPDDR5X server and mobile DRAM, and enterprise SSDs under the Solidigm brand. It acquired Intel's NAND business (later renamed Solidigm) in 2021, making it a top-three NAND supplier.

Market position

SK Hynix is the leading HBM supplier globally, with roughly 50% share in 2025 in a tight race with Samsung and Micron. It is the second-largest DRAM maker overall behind Samsung. On June 24, 2026 the company said it plans to raise up to $29.4 billion through a US stock-market (ADR) listing on Nasdaq, targeted for as soon as July 10 — among the largest listings globally — to capitalize on surging AI memory demand as Nvidia's principal HBM supplier (Source: reuters.com; cnbc.com). The share sale launched on July 6, 2026, seeking 43 trillion won ($28.07 billion) and drawing indications of interest for up to $7 billion from major investors, with SK Hynix's Seoul-listed shares up roughly 273% for the year (Source: reuters.com). The American Depositary Receipts, under the ticker SKHY, were expected to begin trading on July 10, 2026, in what reporting described as the biggest-ever US share sale by a foreign company, following a share-price run of nearly 800% driven by AI memory demand (Source: fortune.com; beincrypto.com). The ADRs began trading on Nasdaq on July 10, 2026 after a completed $26.5 billion share sale — more than seven times oversubscribed and the largest U.S. listing by a foreign company, surpassing Alibaba's $25 billion 2014 record; reporting also ranked it the second-largest U.S. share sale of 2026 after SpaceX's June IPO. The ADRs opened at $170, 14% above the offer price, and closed about 13% higher on the first day (Source: theinformation.com; reuters.com; finance.yahoo.com; investing.com). The same day, SK Hynix's CEO warned of the worst-ever memory supply shortage in 2027, with demand outstripping supply beyond 2030 (Source: reuters.com). Bloomberg analysis framed the US listing as a bet that AI demand is breaking the memory-chip industry's decades-long boom-and-bust cycle (Source: bloomberg.com); CNBC, which placed the listing at $16.5 billion, reported the shares falling more than 10% in Seoul on July 13 on memory-oversupply concerns (Source: cnbc.com). Per Mackintosh's WSJ Streetwise column (May 16, 2026), SK Hynix and Samsung jointly control approximately two-thirds of global DRAM and a larger share of HBM.

Mackintosh's column placed SK Hynix alongside Samsung Electronics as the engines of South Korea's status as the world's best-performing stock market in 2026, a run driven primarily by Samsung Electronics and SK Hynix HBM allocations together with record-high DRAM prices (AI Chip Mania Sows Seeds of Its Own Destruction (Mackintosh, WSJ, May 16 2026)). Mackintosh's frame for SK Hynix, as for Micron Technology and Samsung Semiconductor, is memory-cycle skepticism: he argues that the current low forward price-to-earnings ratios across the HBM duopoly are historically a cycle-peak pattern rather than a bargain signal. He names two structural risks that apply to SK Hynix: memory-efficiency breakthroughs, citing an Alphabet paper from March 2026 that triggered a temporary memory-stock selloff which later recovered; and capacity buildout that is already loaded, citing Micron's $150B program plus new Korean fabs opening, on the view that the added supply which historically turns the cycle is already on order (AI Chip Mania Sows Seeds of Its Own Destruction (Mackintosh, WSJ, May 16 2026)).

The May 17, 2026 Samsung 45,000-worker strike (see Samsung Semiconductor) is, in Mackintosh's frame, bullish for SK Hynix in the short run as the largest substitute supplier of DRAM and HBM during any Samsung disruption, but bearish over the cycle because once the strike resolves and capex completes the cycle dynamics reassert (AI Chip Mania Sows Seeds of Its Own Destruction (Mackintosh, WSJ, May 16 2026)).

Geopolitics and export controls

Along with Samsung, SK Hynix is a strategic asset of the Republic of Korea and a central piece of US-aligned memory supply. Under the October 2024 BIS rule, HBM above specified bandwidth thresholds is itself an export-controlled item when destined for China, making SK Hynix's compliance posture an element of compute governance. SK Hynix operates DRAM fabs in Wuxi, China, which are subject to ongoing export-license scrutiny for advanced equipment, raising the open question of whether a tightening US export-control posture on China-bound HBM could prompt retaliation against those Wuxi operations.

Chinese efforts to close the HBM gap have been a recurring backdrop. On April 22, 2026 a Samsung researcher was sentenced to seven years for leaking DRAM and HBM intellectual property to CXMT in China (Source: english.hani.co.kr).

Relationships

• depends-on: Semiconductor Supply Chain — HBM is the current binding chokepoint.
• supports: Nvidia & TSMC — AI Compute Infrastructure, AMD — Advanced Micro Devices — supplies HBM to both.
• related: Samsung Semiconductor, Micron Technology, Export Controls (AI), Compute Governance, AI Sovereignty, AI Race Dynamics.