Why it matters
SK hynix is the memory supplier whose high-bandwidth memory sits next to the AI accelerators this site already tracks. In the second quarter of 2026 it reported 79.3187 trillion won of revenue and 60.5426 trillion won of operating profit, a 76% operating margin, and said mass shipments of HBM4 had started. One quarter's operating profit was larger than all of 2025, when operating profit was 47.21 trillion won.
The same release shows why the headline net profit should not be used as the operating result. Net profit was 93.9226 trillion won, a reported 118% net margin. Korea Herald, reporting the earnings call, said that figure includes 63.3 trillion won of gains from selling and revaluing investment assets, most of it the stake in Japan's Kioxia.
SK Group affiliate, not a majority subsidiary
At the July 10, 2026 Nasdaq ceremony for the ADR listing, CEO Kwak Noh-Jung said the company joined SK Group in 2012 and thanked more than 48,000 team members. That headcount is his phrase from the speech, not a statutory year-end filing. The same ceremony is the company's public mark for the U.S. listing.
A Form 6-K puts a number on control. As of June 30, 2026, SK square Co., Ltd. owned 146,100,000 shares, 20.50%, and was the largest shareholder. Related persons did not change the percentage. That is influence inside the SK Group, not a majority stake, which is why this profile calls SK square an affiliate.
HBM4 is shipping, HBM4E is sampled
HBM4 is the current flagship. SK hynix said it met customer speed requirements and that mass shipments began in the second quarter of 2026, with output to rise in the second half. It described HBM4 yields as already close to those of HBM3E, which it treats as the mature generation. FY2025 results said HBM revenue had more than doubled and that HBM4 mass-production preparation was finished in September 2025.
NAND is the other line. The Q2 release said 321-layer products are already the largest share of NAND production and are planned to reach about 50% of domestic NAND capacity by the end of 2026. The company also said SOCAMM2 sales grew in the quarter and that shipments of 1c DRAM had begun in earnest. Those are company statements about mix and shipment, not an audited product-level revenue split.
What the numbers are, and what they are not
FY2025, reported January 28, 2026, was 97.1467 trillion won of revenue, 47.2063 trillion won of operating profit, and 42.9479 trillion won of net profit. Q2 2026 then printed 79.3187 trillion won of revenue and 60.5426 trillion won of operating profit. First-half 2026 revenue was 131.9 trillion won. Cash and equivalents were 88 trillion won at June 30, and interest-bearing debt was 18.6 trillion won, which the company translated into 69.4 trillion won of net cash.
Management guided 2026 capital spending to the high 40 trillion won range and said the spending pulls forward M15X and prepares output for the Yongin Phase 1 cleanroom in early 2027. It also said long-term agreements with about 10 customers were done, typically for five years, with purchase commitments and deposits. It did not say what share of sales those contracts cover. The Q2 figures were labeled preliminary.
What to watch
The dated tests are HBM4E volume production in 2027 and the Yongin Phase 1 cleanroom in early 2027. HBM4E samples were already with customers in the first half of 2026. Talks on 2027 HBM volume and price were still open at the July earnings call. A separate company plan for a southwestern semiconductor cluster, measured in hundreds of trillions of won, is a longer-range vision and is not the 2026 capex guide.
The other thing to watch is the gap between operating profit and net profit. As long as investment gains, especially Kioxia, dominate the bottom line, comparisons with TSMC or Samsung on net margin will mislead. The operating margin, 76% in the quarter, is the figure the company itself put next to chip sales.