SK Hynix's Two-Front Push: Nvidia's HBM4 Seal of Approval Meets a Japanese Expansion Gamble

SK Hynix wins Nvidia's HBM4 approval for AI GPUs, plans record investments in Korea and a potential Japan fab, boosting shares.

The memory chip giant is moving on multiple fronts at once. SK Hynix has secured Nvidia's certification for its next-generation HBM4 memory — a critical milestone for the upcoming "Vera Rubin" AI GPU platform — while simultaneously weighing a first-ever manufacturing foothold in Japan.

Jensen Huang, Nvidia's chief executive, confirmed that SK Hynix successfully cleared the certification process for HBM4 supply. Reports suggest the Korean chipmaker will capture the lion's share of Nvidia's HBM4 volume allocation. To tighten those customer bonds further, the company is expanding its High Bandwidth Memory design team in San Jose, California, where direct co-design of base dies and three-dimensionally stacked DRAM with major US hyperscalers will now be orchestrated.

A Japanese Factory on the Horizon

Separately, SK Hynix is exploring the construction of a memory chip plant in Japan's Miyagi prefecture. According to reports from Reuters and Hankyoreh, the investment could reach double-digit trillions of won. If realized, it would mark the first major production site of a South Korean chipmaker on Japanese soil. Group chairman Chey Tae-won recently toured the region, though a final investment decision has yet to be made.

The potential Miyagi project sits within a broader wave of expansion announcements. On August 7, the company unveiled plans for new factories in Yongin and Cheongju, responding to surging AI-era demand for memory chips. The Cheongju M17 facility will span roughly 680,000 square meters, with groundbreaking scheduled for February next year and the first clean room opening slated for December 2028. The master plan commits 600 trillion won to the Yongin semiconductor cluster and an additional 100 trillion won to expanding the Cheongju site.

The board had earlier approved a 54.3 trillion won investment program in early August to secure medium- to long-term production capacity. That breaks down to 35.2 trillion won for the new "Y2" fab in Yongin and 19.1 trillion won for the NAND-focused M17 plant in Cheongju. Management is also accelerating the production ramp at the M15X facility in Cheongju, part of a revised capital expenditure plan of 40 trillion won for the current fiscal year — a 45 percent increase over the prior year.

Market Momentum and a Record Quarter

The expansion push comes alongside a notable run-up in the share price. On Thursday, the stock surged 12.73 percent, extending a recovery that had already delivered 15.0 percent gains the previous week. Over the past seven trading sessions, the cumulative advance stands at 5.2 percent. Even so, the shares remain 42 percent below their June 52-week high, leaving considerable room for further upside should the positive news flow persist.

The recent rally follows a landmark capital return announcement on August 19, when SK Hynix unveiled a 40 trillion won share buyback and raised its payout ratio to more than 50 percent of cumulative free cash flow between 2025 and 2027. Since that announcement, the stock has gained 15.7 percent. On Friday, the shares continued climbing, trading 2.3 percent higher at 1,730,000 won after closing Thursday at 1,691,000 won.

The company's financial firepower is considerable. In the second quarter, SK Hynix posted record results: revenue of 79.3187 trillion won, operating profit of 60.5426 trillion won — an operating margin of 76 percent — and net income of 93.9226 trillion won. Interestingly, the stock fell 9.6 percent on those results, as analysts had anticipated even stronger figures, with the shortfall attributed to HBM4 deliveries trailing expectations.

Long-Term Supply Deals and Regulatory Details

The aggressive expansion strategy rests on substantial AI-related supply agreements. Late July saw the SK Group and Nvidia announce a partnership valued at more than 500 billion dollars, encompassing a long-term supply arrangement for AI memory chips from SK Hynix. During the second quarter, the company also signed long-term supply contracts with ten customers and commenced mass production of HBM4 chips, with output expected to scale up in the second half of the year.

In a separate regulatory filing, SK Hynix disclosed the transfer of 82 treasury shares at 1,500,000 won each to independent directors. The company retains 1,625,769 treasury shares, representing 0.2 percent of total shares outstanding. The transaction is tied to the ongoing execution of the 40 trillion won buyback and cancellation program, which runs until November 19.

The broader semiconductor market is clearly strengthening. The Semiconductor Industry Association reported second-quarter global semiconductor sales of 403.3 billion dollars, up 35.1 percent quarter over quarter. June alone saw worldwide revenues of 134.5 billion dollars — more than double the year-earlier figure.

Whether the Miyagi factory ultimately moves forward remains an open question. For investors, however, the signal is unambiguous: SK Hynix is not letting its generous shareholder distributions slow its capacity ambitions. The company is simultaneously expanding across multiple countries while cementing its technological edge with Nvidia's HBM4 endorsement — a dual-track strategy that will test whether record investment can translate into sustained cash flow.