By Kwanwoo Jun

Shares of Samsung Electronics and SK Hynix surged to multiyear highs after the South Korean memory-chip makers struck initial agreements with ChatGPT maker OpenAI as part of a global artificial-intelligence push.

OpenAI Chief Executive Sam Altman signed letters of intent with Samsung Group affiliates and SK Hynix on Wednesday to team up to establish the global AI infrastructure, including next-generation data centers, under his company-led Stargate initiative. No deal value was disclosed.

The partnership includes potential megadeals for the South Korean companies to help OpenAI secure a massive volume of powerful AI chips, including high-bandwidth-memory products, and build OpenAI's Stargate data centers, according to statements from Samsung and SK Hynix.

On South Korea's main stock market on Thursday, shares of HBM leader SK Hynix advanced as much as 12% to 404,500 won, equivalent to $288.35, while Samsung Electronics climbed as much as 5.0% to 90,300 won. The rally boosted their combined market value by more than $30 billion, pushing the benchmark Kospi 3% higher to a record.

SK Hynix said Wednesday that it will be a key HBM supplier for OpenAI's Stargate project and boost its AI-chip production capacity to meet future demand for an estimated 900,000 semiconductor wafers a month. The companies will also collaborate to build AI data centers in South Korea's southwest, SK Hynix said.

Samsung, which is also partnering with OpenAI, on Wednesday said its construction and trading affiliate, Samsung C&T, and shipbuilding affiliate, Samsung Heavy Industries, will jointly develop floating data centers. Its information-technology services subsidiary, Samsung SDS, will help design and operate Stargate AI data centers.

Samsung Electronics, which has lagged behind SK Hynix in supplying advanced HBM3E products, is stepping up efforts to catch up in supplying next-generation HBM4 products, currently under development for major AI-chip clients.

The two Korean chip makers dominate the global HBM market with a combined market share of around 80%, according to estimates by market-research firm Counterpoint Research. SK Hynix is the market leader with a 62% share as of the second quarter, followed by Micron Technology with 21% and Samsung with 17%.

OpenAI and other major global equity funders in Stargate earlier committed an initial $100 billion, with plans to invest up to $500 billion over the next four years.

News Corp, owner of Dow Jones Newswires and The Wall Street Journal, has a content-licensing partnership with OpenAI.

Write to Kwanwoo Jun at kwanwoo.jun@wsj.com

(END) Dow Jones Newswires

October 02, 2025 00:55 ET (04:55 GMT)

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