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AI memory chip boom reshapes South Korea's stock market

AI memory chip boom reshapes South Korea's stock market

Money Moves

Samsung and SK Hynix propel KOSPI past 6,000 as global AI infrastructure buildout devours memory chips

February 25th, 2026: KOSPI surpasses 6,000 for the first time

Overview

Updated May 29

South Korea's benchmark KOSPI stock index crossed 6,000 points for the first time on February 25, 2026. It completed its climb from 5,000 to 6,000 in just 34 trading days, the fastest thousand-point advance in the index's history.

The index has gained 43% since January and 76% in 2025, making Seoul's market the best-performing major bourse in the world. Two companies drove most of the move: Samsung Electronics and SK Hynix. They account for roughly 40% of the KOSPI's market capitalization and produce approximately 80% of the world's high-bandwidth memory (HBM) chips, the specialized components that AI data centers cannot run without.

The rally reflects a structural shift in the global semiconductor industry. Every major technology company building AI infrastructure, from Nvidia to hyperscale cloud providers, needs exponentially more memory per server. The factories that make those chips are concentrated in South Korea.

With 2026 HBM production already sold out and memory prices rising 40–70%, Samsung and SK Hynix posted record profits in 2025. South Korea's government has overhauled corporate governance laws to strengthen shareholder rights, narrowing the longstanding valuation gap that made Korean equities cheaper than global peers. The question now is whether this is a durable repricing of Korean assets or a concentration risk masquerading as a boom.

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Key Indicators

6,083
KOSPI closing level (Feb 25)
First close above 6,000 in the index's history
34 days
5,000 to 6,000 sprint
Fastest thousand-point climb in KOSPI history, surpassing the 1999 record
$3.5T
Combined KOSPI market cap
Total market capitalization of listed companies surpassed 5,000 trillion Korean won for the first time
80%
Korean share of global HBM
Samsung and SK Hynix together produce roughly four out of every five high-bandwidth memory chips worldwide
$54.6B
Projected 2026 HBM market
Bank of America estimates the high-bandwidth memory market will grow 58% year-over-year
49%
SK Hynix operating margin (2025)
Full-year operating margin on 97.1 trillion won in revenue, driven by HBM sales that more than doubled

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People Involved

Kwak Noh-Jung
Kwak Noh-Jung
President and Chief Executive, SK Hynix
Leading company through record-breaking performance
 Jun Young-hyun
Jun Young-hyun
Vice Chairman and Co-Chief Executive, Samsung Electronics (Device Solutions)
Leading Samsung's semiconductor recovery and HBM4 production ramp
 Lee Jae Myung
Lee Jae Myung
President of South Korea
Advancing corporate governance reforms and stock market development agenda

Organizations Involved

SK Hynix
SK Hynix
Memory manufacturer
World's largest high-bandwidth memory producer; all 2026 HBM capacity sold out

South Korea's second-largest chipmaker holds a dominant 62% share of global high-bandwidth memory shipments, making it the most critical supplier in the AI data center buildout.
Samsung Electronics
Samsung Electronics
Technology company
Largest KOSPI-listed company by market cap; ramping HBM4 production to close gap with SK Hynix

The world's largest memory chip maker by total volume is aggressively expanding AI chip production after falling behind SK Hynix in the race to qualify high-bandwidth memory with key customers.
Korea Exchange (KRX)
Korea Exchange (KRX)
Stock Exchange
Operating the world's best-performing major equity market

South Korea's sole securities exchange operator administers the KOSPI and KOSDAQ indices and has been implementing the government's Value Up program to attract global investors.

Timeline

February 2024 February 2026

12 events Latest: February 25th, 2026 · 6 months ago Showing 8 of 12
Tap a bar to jump to that date

  1. KOSPI surpasses 6,000 for the first time

    Latest Market

    The index reaches an intraday high of 6,144 and closes at 6,083, completing the fastest thousand-point advance in its history. SK Hynix's share price breaks through 1,000,000 won, and Samsung hits 200,000 won. Combined KOSPI market capitalization exceeds 5,000 trillion won (approximately $3.5 trillion).

  2. Samsung posts record Q4 profit; announces HBM4 mass production

    Earnings

    Samsung Electronics reports Q4 operating profit of 20.1 trillion won, up 209% year-over-year, as memory prices surged 40–50%. The company announces it will begin mass shipments of HBM4 in February, closing the technology gap with SK Hynix.

  3. SK Hynix surpasses Samsung in annual profit for the first time

    Earnings

    SK Hynix reports 2025 operating profit of 47.2 trillion won with a 49% operating margin, beating Samsung's semiconductor division for the first time in history. The result confirms SK Hynix's transformation from industry follower to leader in the AI memory era.

  4. KOSPI crosses 5,000 for the first time

    Market

    The index clears another historic threshold, up 43% year-to-date in just three weeks of trading. Individual investors drive record buying in semiconductor stocks.

  5. Samsung and SK Hynix seek 70% server memory price hikes

    Industry

    Both companies push for dramatic price increases on server DRAM for the first quarter of 2026, signaling that surging AI demand has flipped the memory market from buyer-controlled to seller-controlled.

  6. KOSPI ends 2025 up 76%—its best year since 1999

    Market

    The index closes at 4,214 points, nearly doubling from its 2024 level. The annual gain of 75.6% makes it the strongest-performing major market globally, surpassing Japan's Nikkei 225 (up 26%) and the U.S. S&P 500.

  7. SK Hynix reports record Q3; confirms all 2026 HBM capacity sold out

    Earnings

    SK Hynix posts record quarterly revenue and operating profit, driven by HBM3E sales that more than doubled. The company confirms demand is so strong that its entire 2026 production of high-bandwidth memory is already committed to customers.

  8. KOSPI crosses 4,000 for the first time

    Market

    The index reaches a new milestone as foreign investors pour 9.8 trillion won into Samsung and SK Hynix over six weeks, betting on rising memory chip prices and AI demand. The KOSPI becomes the world's top-performing major index.

  9. National Assembly passes Commercial Act amendments

    Legal

    South Korea's legislature amends the Commercial Code to require directors to act in the interests of all shareholders, not just the company, and raises the minimum share of independent directors on boards of public companies from one-quarter to one-third.

  10. Lee Jae-myung wins snap presidential election

    Political

    Lee takes office on a platform embracing corporate governance reform and capital market development. His administration forms the KOSPI 5000 Special Committee and backs strengthened shareholder protections.

  11. KOSPI closes 2024 down nearly 10% despite global tech rally

    Market

    The KOSPI ends 2024 at 2,399 points, falling 9.6% for the year while global peers rallied. Political instability and Samsung's struggles qualifying HBM chips with Nvidia weighed on sentiment.

  12. South Korea launches Corporate Value-Up program

    Policy

    The government introduces a corporate governance reform initiative modeled on Japan's successful program, offering tax incentives for companies that improve shareholder returns and transparency. The "Korea Discount"—a roughly 30% valuation gap between Korean and global equities—is the explicit target.

Historical Context

3 moments from history that rhyme with this story — and how they unfolded.

January 1999 – March 2000

Nasdaq's 86% surge in 1999 before the dotcom crash

The Nasdaq Composite gained 86% in 1999, its best year ever, driven by investor enthusiasm for internet and technology companies. Twelve large-cap stocks rose over 1,000% that year. The index peaked at 5,048 on March 10, 2000. Within two and a half years, it had fallen 77% to 1,139, erasing nearly all gains from the boom.

Then

Trillions of dollars in paper wealth vanished. Hundreds of technology companies went bankrupt. The U.S. economy entered a mild recession in 2001.

Now

Companies with real revenue and market position—Amazon, Apple, Google—survived and eventually grew far beyond their dotcom-era peaks. The Nasdaq did not permanently regain its 2000 high until 2015.

Why this matters now

The KOSPI's 76% gain in 2025 and 43% year-to-date in 2026 echo the velocity of Nasdaq's late-1990s surge. However, the comparison has limits: Samsung and SK Hynix are highly profitable companies with sold-out production capacity, unlike the revenue-free startups that inflated the dotcom bubble. The parallel is most useful as a reminder that rapid index gains driven by sector concentration—technology then, AI memory now—carry inherent fragility.

January – December 1999

South Korea's 1999 post-crisis stock market boom

Following the devastation of the 1997–1998 Asian financial crisis, the KOSPI surged from below 600 to above 1,000 in 1999, gaining over 80% in a single year. The rally was fueled by a post-crisis restructuring of Korean conglomerates, the rise of Samsung as a global technology brand, and speculative enthusiasm for internet stocks.

Then

The rally faded quickly. By late 2000, the KOSPI had fallen back below 600 as the global dotcom bust hit Korean technology stocks. The index did not sustain levels above 1,000 until 2005.

Now

The crisis-era reforms—bank restructuring, chaebol transparency requirements, and market liberalization—laid the foundation for Korea's emergence as a major technology economy over the following two decades.

Why this matters now

The current rally is the fastest since that 1999 surge—a direct comparison Korean market commentators are making. Both episodes combined structural reform with sector-specific enthusiasm. The 1999 precedent suggests that while reforms can create lasting value, the speed of market gains often overshoots the pace of underlying improvement.

January 2023 – March 2024

Japan's Nikkei recovery after governance reforms (2023–2024)

After trading below its 1989 peak for 34 years, Japan's Nikkei 225 index surged past 39,000 in February 2024, finally surpassing the all-time high set during the Japanese asset bubble. The rally was driven by Tokyo Stock Exchange governance reforms launched in 2023 that pressured companies to improve capital efficiency and return cash to shareholders—the same template South Korea's Value Up program explicitly copied.

Then

Japanese equities attracted record foreign inflows as investors embraced the governance reform thesis. Warren Buffett's high-profile investments in Japanese trading houses helped legitimize the trade globally.

Now

The Nikkei continued climbing through 2025, demonstrating that governance reforms can durably close a valuation discount. The "Japan trade" became a template for emerging market reform stories worldwide.

Why this matters now

South Korea explicitly modeled its Value Up program on Japan's reforms and is now experiencing a similar—but faster—rerating. The KOSPI's price-to-book ratio has risen from 0.8 to 1.25, mirroring Japan's trajectory. The parallel suggests the governance component of Korea's rally has a proven precedent, though Korea's simultaneous semiconductor boom makes the dynamics more complex.

Sources

(15)
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Bloomberg The Korea Times Seoul Economic Daily The Korea Herald CNBC SK Hynix Newsroom KED Global Kim & Chang The Edge Singapore MarketScreener CNBC CNBC KED Global Seoul Economic Daily The Korea Times