SK Hynix Overtakes Samsung Electronics as Korea’s Most Valuable Stock for First Time in 25 Years; Kospi Holds 9,100

SK Hynix overtook Samsung Electronics to become South Korea’s most valuable listed company, marking the first change in the Kospi’s top stock in 25 years and seven months. The shift follows a steady rally driven by expanding artificial intelligence spending and the company’s early lead in high-bandwidth memory, or HBM. The reversal is a symbolic sign that leadership in the domestic stock market is shifting from electronics makers to AI semiconductor companies in the AI era.

On June 22, SK Hynix closed up 5.57% at 2.918 million won. Its market capitalization reached 207.96655 trillion won, surpassing Samsung Electronics’ 206.08132 trillion won by 1.88523 trillion won. The stock opened down 1.30% at 2.728 million won, quickly reversed course and climbed as much as 6.55% intraday to 2.945 million won, holding near session highs through the day.

Samsung Electronics fell 0.14% to 353,500 won. The stock opened down 3.11% at 343,000 won and rose as high as 363,000 won before giving up those gains after swinging between advances and losses, ceding the top spot by market value.

Samsung still leads when its preferred shares are included. The combined market capitalization of Samsung Electronics and Samsung Electronics Preferred stood at 224.15473 trillion won, ahead of SK Hynix by 16.18818 trillion won. Samsung Electronics Preferred rose 1.46% to 225,250 won, lifting its market capitalization to 18.07341 trillion won. SK Hynix does not have separately listed preferred shares.

SK Hynix has been one of the biggest beneficiaries of rising AI investment thanks to its HBM-centered business structure. Its shares have surged more than 340% this year, outpacing Samsung Electronics’ roughly 198% gain over the same period and propelling the company to the top spot by market value.

Securities firms expect SK Hynix to rise further. Park Jun-young, an analyst at Hanwha Investment & Securities, said the company is no longer one marked by extreme earnings volatility and is transforming into one capable of generating a consistently high level of profit.

The Kospi swung around the 9,000 level on June 22 before ending slightly higher. The benchmark closed up 0.69% at 9,114.55. It opened down 1.08% at 8,954.43, fell to near the 8,900 level, then rebounded and touched 9,253.00.

SK Square, SK Hynix’s largest shareholder, jumped 10.67% to 1.97 million won. Among Samsung group stocks, Samsung Electro-Mechanics fell 1.85%, Samsung Life Insurance dropped 9.36% and Samsung Biologics slid 5.75%, while Samsung C&T rose 5.8%. Within Hyundai Motor Group, Hyundai Motor fell 5.22% and Kia lost 2.26%.

The Kosdaq closed up 0.19% at 968.40. Individuals were net sellers of 463 billion won, while foreign investors were net buyers of 311 billion won and institutions bought a net 150 billion won, helping support the gain. Alteogen, the Kosdaq’s most valuable stock, fell 0.85% to 350,500 won. Other large-cap names also mostly declined, including EcoPro BM, down 1.59%, EcoPro, down 1.29%, and Rainbow Robotics, down 2.88%. Semiconductor materials, parts and equipment makers outperformed, with Jusung Engineering up 2.49% and Wonik IPS rising 10.58%.

Securities firms expect South Korean stocks to extend their gains. Byun Jun-ho, an analyst at IBK Investment & Securities, said the Kospi is likely to keep testing higher levels in the short term within an 8,000-11,000 range. Uptrends in leading economic indicators and exports remain intact, while semiconductor-led earnings forecasts and profitability improvements are also continuing.

Kang Kyung-ju, Hankyung.com reporter qurasoha@hankyung.com