Samsung Electronics (005930) · SK Hynix (000660)
Samsung and SK Hynix Lead KOSPI Surge Amid HBM4 Breakthrough
The South Korean equity market witnessed a significant rally on Thursday, March 19, 2026, as semiconductor heavyweights Samsung Electronics and SK Hynix propelled the KOSPI index to new heights. The surge is primarily attributed to a massive Samsung SK Hynix HBM4 supply milestone following NVIDIA’s GTC 2026 conference, where both companies showcased their latest advancements in High Bandwidth Memory (HBM) technology for next-generation AI accelerators.
According to data from the Korea Exchange (KRX), the KOSPI index advanced significantly during the morning session, with Samsung Electronics reclaiming the 200,000 won milestone and SK Hynix hitting a record intraday high. Foreign institutional investors have been net buyers of Korean tech stocks, buoyed by the “Vera Rubin” AI platform requirements which rely heavily on 16-high HBM4 memory stacks.
The Samsung SK Hynix HBM4 Supply Race
Samsung Electronics officially unveiled its HBM4E AI memory chips earlier this week, signaling a fierce competition with SK Hynix for NVIDIA’s 2026 supply contracts. Reports from industry analysts at TrendForce and Hankyung suggest that while SK Hynix currently holds over half of NVIDIA’s total HBM supply, Samsung is aggressively scaling its 1c DRAM capacity to lead shipments specifically for the upcoming Vera Rubin architecture. As noted on kstocks.net, this shift represents a critical pivot for Samsung as it aims to bridge the market share gap in the premium AI memory segment.
SK Hynix, on the other hand, has already begun providing HBM4 samples to NVIDIA this month, maintaining its first-mover advantage. The company’s established mass production system for 12-high and 16-high HBM3E products continues to generate robust cash flows, which are being reinvested into the expansion of its M15X fab in Cheongju and the Yongin Semiconductor Cluster.
Market Impact and Future Outlook
The Samsung SK Hynix HBM4 rivalry is not just a corporate battle but a significant macro driver for the South Korean economy. Together, these two giants now account for over 40% of the total KOSPI market capitalization. Market analysts suggest that the “Memory Boom 2.0,” driven by generative AI demand, could sustain the current bull run through the second half of 2026. The Bank of Korea (BOK) and the Ministry of Economy and Finance have highlighted that semiconductor exports remain the primary engine for South Korea’s trade surplus recovery.
Investors are also closely monitoring the performance of other KOSPI leaders like NAVER and Kakao, which are benefiting from the broader AI ecosystem expansion. However, the spotlight remains firmly on the semiconductor sector as the global supply chain stabilizes around South Korean memory solutions. The integration of 16-Hi HBM4 into AI servers is expected to double the memory bandwidth compared to previous generations, further solidifying the dominance of Samsung and SK Hynix in the global tech landscape.
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About the Author
Johnny Lee
Seoul-based full-time professional and individual investor with 5 years of active experience in the Korean stock market. My approach combines value investing with medium-term swing trading across a diversified portfolio. In 2025, my personal account delivered a 72.9% return, significantly outperforming the KOSPI benchmark. I started KStocks to bring the Korean investor perspective directly to a global English-speaking audience.
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