SK hynix vs Samsung: the memory war inside Nvidia's AI boom

<p><em>Special Reporting from LSN News, adapted from today's Asia Behind the Headlines episode. <a href="https://youtu.be/2kRRn27pBSk" target="_blank" rel="noopener">Watch the video on YouTube.</a></em></p>

<p>Samsung Electronics took 33% of global high-bandwidth memory (HBM) revenue in the second quarter of 2026, up from 15% a year earlier, according to Counterpoint Research. SK hynix still leads with 50%, but it held 64% a year ago. Micron is third with 18%. The numbers show how quickly the most valuable chip in the AI supply chain has become a two-company contest, and both companies are South Korean.</p>

<h2>From one leader to a race</h2>

<p>HBM is memory stacked in layers and packaged next to AI processors such as Nvidia's GPUs. In the last two generations, HBM3 and HBM3E, SK hynix built what the Korea Herald calls a commanding lead as a key supplier to Nvidia. Samsung fell behind. A year ago its share was below Micron's.</p>

<p>The contest has moved to the sixth generation, HBM4, the memory for Nvidia's next AI platform, Vera Rubin. Samsung has been shipping commercial HBM4 since February, the Korea Herald reports. SK hynix said in its second-quarter results on 29 July that it "began mass shipments of HBM4 in the second quarter and will ramp up production in the second half of the year." Counterpoint said most HBM revenue still comes from HBM3E, and it expects Samsung's share to rise gradually as HBM4 shipments grow. Counterpoint also expects most Rubin-based products to use 12-layer HBM4.</p>

<p>Samsung is confident. "We expect HBM4 to account for more than 60 percent of our total HBM revenue in the second half," Samsung executive vice president Kim Jae-june said, as quoted by the Korea Herald. SK hynix is just as sure of its position: "Our accumulated competitiveness in time to market, product performance, mass-production yield, quality and customer trust are differentiators that cannot be replicated in a short period of time," it said on its own call.</p>

<h2>Record profits, fragile prices</h2>

<p>The money at stake is huge. Samsung's preliminary third-quarter operating profit was about 107.4 trillion won, or roughly $80 billion, on sales of about 195 trillion won. It is the first time the company has passed 100 trillion won in a quarter. SK hynix reported a record second-quarter operating profit of 60.54 trillion won, a 76% operating margin, and says it has long-term supply agreements with around 10 customers.</p>

<p>Markets have turned volatile anyway. On Thursday 15 October, Samsung shares fell 9.48% and SK hynix fell 11.06%, according to Yonhap and the Seoul Economic Daily. South Korea's Kospi dropped 7.57% to 5,554.22 and tripped a circuit breaker, as hotter-than-expected U.S. inflation data and doubts about returns on AI investment landed together.</p>

<h2>The bottleneck may be in Taiwan</h2>

<p>Making more memory is not the only constraint. HBM has to be joined to GPUs through advanced packaging, including TSMC's chip-on-wafer-on-substrate process. As the Korea Herald notes, even with enough memory, limited packaging capacity could cap the number of finished AI accelerators.</p>

<h2>Our read</h2>

<p>This is no longer a one-company market. Samsung is closing the gap quickly. SK hynix still earns half of HBM revenue, has the longer production record, and is ramping HBM4 now. The next few quarters of shipments will decide how far the shares move. Samsung is due to publish its detailed third-quarter results later this month. For Asia, the main story is concentration more than the winner. The memory for the world's AI build-out comes mainly from two Korean companies, it passes through one Taiwanese packager, and its value can swing by double digits in a single session. That makes Seoul and Hsinchu as important to the AI cycle as Silicon Valley, and exposes Korea's stock market to every twist in it.</p>

<h2>Sources</h2>

<ul>

<li><a href="https://counterpointresearch.com/en/insights/global-dram-and-hbm-market-share" target="_blank" rel="noopener">Counterpoint Research, 2 Sep 2026</a></li>

<li><a href="https://en.yna.co.kr/view/AEN20260903010700320" target="_blank" rel="noopener">Yonhap, 3 Sep 2026</a></li>

<li><a href="https://www.koreaherald.com/article/10862994" target="_blank" rel="noopener">Korea Herald, 4 Sep 2026</a></li>

<li><a href="https://www.koreaherald.com/article/10897751" target="_blank" rel="noopener">Korea Herald, 9 Oct 2026</a></li>

<li><a href="https://news.skhynix.com/en/q2-2026-business-results/" target="_blank" rel="noopener">SK hynix Newsroom, 29 Jul 2026</a></li>

<li><a href="https://en.sedaily.com/finance/2026/07/29/sk-hynix-locks-in-long-term-deals-with-10-clients-ramps-up" target="_blank" rel="noopener">Seoul Economic Daily, 29 Jul 2026</a></li>

<li><a href="https://news.samsung.com/global/samsung-electronics-announces-earnings-guidance-for-third-quarter-2026" target="_blank" rel="noopener">Samsung Newsroom, 8 Oct 2026</a></li>

<li><a href="https://www.cnbc.com/2026/10/08/samsung-q3-earnings.html" target="_blank" rel="noopener">CNBC, 8 Oct 2026</a></li>

<li><a href="https://en.sedaily.com/news/2026/10/15/kospi-falls-for-7th-day-erasing-1193-trillion-won-in-value" target="_blank" rel="noopener">Seoul Economic Daily, 15 Oct 2026</a></li>

<li><a href="https://en.yna.co.kr/view/AEN20261015007251320" target="_blank" rel="noopener">Yonhap, 15 Oct 2026</a></li>

</ul>