South Korean memory chipmaker SK Hynix said Friday that it was ready to mass produce its next-generation high-bandwidth memory chips, staying ahead of rivals and sending the company’s stock soaring. 

HBM is a type of memory that is used in chipsets for artificial-intelligence computing, including in chips from global AI giant Nvidia — a major client of SK Hynix. 

SK Hynix said earlier this year that it had shipped samples of its HBM4 chips to customers, as it sought to beat competitors including Samsung Electronics and Micron Technologies.

According to its announcement Friday, the company has finished its internal validation and quality assurance process for HBM4 and is ready to manufacture those at scale.

“Completion of HBM4 development will be a new milestone for the industry,” said Joohwan Cho, head of HBM development at SK Hynix.

HBM4 is the sixth generation of HBM technology — a type of Dynamic Random Access Memory, or DRAM. DRAM can be found in personal computers, workstations and servers and is used to store data and program code.

SK Hynix’s latest HBM4 product has doubled bandwidth and increased power efficiency by 40% compared to the previous generation, according to the company.  

Notably, HBM4 is expected to be the main AI memory chip needed for Nvidia’s next-generation Rubin architecture — a more powerful AI chip for global data centers — said Dan Nystedt, vice-president at TriOrient, an Asia-based private investment firm with a focus on semiconductors.

“SK Hynix is a key supplier for Nvidia, and the announcement shows it remains far ahead of rivals,” he said.

Samsung Electronics and Micron have struggled to catch up to SK Hynix in HBM, as it builds on its segment leadership and benefits from being Nvidia’s main HBM supplier. 

However, the companies have made some progress. Micron has also shipped samples of its HBM4 products to customers, while Samsung has reportedly been working to get its HBM4 chips certified by Nvidia. 

“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,” said MS Hwang, research director at Counterpoint Research, covering memory solutions.

SK Hynix shares rose more than 7% Friday to hit their highest since 2000, following its chip announcement, bringing year-to-date gains to nearly 90%. Shares of Samsung Electronics and Micron have risen over 40% and nearly 80% in 2025, respectively.

SK Hynix posted record operating profit and revenue for its June-quarter, thanks to strong HBM demand, which accounted for 77% of its overall revenues. The company’s market capitalization has increased by more than $80 billion since the start of the year, according to data from S&P Capital IQ.

The firm expects to double HBM sales for the full year compared to 2024, and for demand from AI to continue to grow into 2026.