SK Hynix Stock Soars 7% as Chip Maker Announces HBM4 Production

Chip maker SK Hynix has finalized the internal quality assurance and certification process for its next-generation high-bandwidth memory chips, HBM4. According to Reuters, the South Korean firm on Friday said it was ready for mass SK Hynix HBM4 production, having set up a production system for clients. SK Hynix stock soared 7% on September 12, 2025 after the announcement.

Key HBM Supplier for NVIDIA

SK Hynix is a major HBM supplier for AI chip maker NVIDIA. In a statement posted on its website in March 2025, SK Hynix said samples of the HBM4 12-layer chip had been shipped to customers. At the time, the company said it planned to complete mass production preparations for the chip in the second half of 2025.

HBM4 is the sixth generation of HBM, which is a form of Dynamic Random Access Memory (DRAM) standard that was first manufactured in 2013. DRAM is used in servers, workstations, and personal computers to store program code and data.

This type of memory is created by stacking chips vertically to reduce space and power consumption to facilitate processing of huge volumes of data generated by complex AI applications. SK Hynix has doubled the bandwidth in its HBM4 chip and enhanced its power efficiency by 40% compared to the previous generation. “Completion of HBM4 development will be a new milestone for the industry,” Head of HBM Development at SK Hynix Joohwan Cho said.

Maintaining a Commanding Lead in HBM4 Chips

By announcing mass production of HBM4 chips, SK Hynix plans to maintain a strong lead in the chip manufacturing industry. It is expected that the next-generation HBM memory for AI will be the main chip that NVIDIA will need for its Rubin architecture, which is a more powerful AI chip designed for global data centers.

“Despite the shifting competitive landscape, we anticipate SK Hynix will maintain a commanding position, potentially securing around 50% of the HBM market share by 2026,” Counterpoint Research Director MS Hwang said.

Micron Technologies and Samsung Electronics have made limited progress in matching SK Hynix’s HBM technology. Samsung is reportedly working on getting NVIDIA to certify its HBM4 chips while Micron has dispatched samples of its chips to customers.

“Samsung Electronics has trailed in the HBM race so far, but is aiming to narrow the gap by adopting the more advanced 1c-nanometer node, compared with rival SK Hynix’s 1b-nanometer process for HBM4 chips,” Senior Analyst at NH Investment & Securities, Ryu Young-ho said.

In January 2025, Samsung’s profit dropped by 30% quarter-on- quarter due to market slowdown and weakening global chip demand.

SK Hynix Market Performance

In the market, SK Hynix stock gained over 7% on September 12, 2025, following the HBM4 chip production announcement. The share price surge brought the stock’s year-to-date gains close to 90%. Samsung Electronics stock has gained over 40% in 2025.

In January 2025, SK Hynix shares dropped 2.7% despite reporting a 12% increase in its quarter four revenue. At the time, the chip maker attributed its strong quarterly earnings to strong demand for AI memory, particularly its HBM technology.

In the second quarter, SK Hynix reported that its HBM sales accounted for 77% of its overall revenue. Since January 2025, the company’s market valuation has increased by over 80%. The South Korean chip maker expects to double its HBM sales in 2025 as it expects demand for AI to continue rising into 2026.

In 2026, SK Hynix’s HBM market share is projected to decline modestly to the low 60% range, down from 66% in 2025. This is largely due to the company’s first-mover advantage resulting from the early HBM4 supply to top customers.