SK Hynix Prepares HBM4 Production to Defend Market Lead Over Rivals

SK Hynix (000660.KS) announced on Friday that it has completed internal certification of its HBM4 (high-bandwidth memory 4) chips and established a production system, positioning itself to maintain its dominance in the advanced memory market.

Key Developments

  • In March 2025, SK Hynix shipped 12-layer HBM4 chip samples to customers.

  • The company aims to complete mass production preparations for these chips within H2 2025.

  • Shares rose 7% to a record high of 328,500 won ($236.71), outperforming the benchmark KOSPI’s 1.5% gain.

Market Context

  • HBM technology: First introduced in 2013, HBM stacks DRAM vertically to save space, cut power use, and process vast data volumes required by AI workloads.

  • Market share: SK Hynix is projected to hold about 60% of the HBM market in 2026, down slightly from its current 66%, according to Meritz Securities.

  • Customers: Nvidia remains its largest client, though Samsung Electronics and Micron supply smaller volumes.

Rival Strategies

  • Samsung Electronics: Plans to use a 1c-nanometer node for HBM4, compared to SK Hynix’s 1b-nanometer process, signaling a push to catch up despite a weaker track record. Samsung already provided HBM4 samples to customers and plans to start supply in 2026.

  • Micron: Competing with custom-built logic dies (“base dies”) that make it harder for customers to switch suppliers.

Industry Impact

  • SK Hynix’s first-mover advantage in HBM4 is expected to secure early contracts with major AI players like Nvidia.

  • Analysts note that customer-specific base dies mark a technological shift that could lock buyers into long-term supplier relationships.

Market Performance YTD

  • SK Hynix: +88.9%

  • Samsung Electronics: +41.7%

  • Micron (Nasdaq): +78.9%

  • KOSPI benchmark: +41.5%