South Korea's Top Conglomerates Lose Over $800 Billion in Market Value
Seoul, Sunday, 25 October 2026.
South Korea’s premier business groups lost $830 billion in October 2026, with tech giants Samsung and SK driving an astonishing 90% of the total decline amid mounting AI profitability concerns.
October Market Rout Erases Over $800 Billion in Market Cap
South Korea’s Kospi index suffered an 18.8% decline in October 2026, resulting in the evaporation of approximately 1,101 trillion won ($830.7 billion) in combined market capitalization from the nation’s top ten conglomerates [1][2][3][5]. The sell-off, which concluded on October 23, 2026, saw these business groups’ total valuation plummet from 4,472.5308 trillion won at the end of September to 3,371.441 trillion won, marking the most significant monthly loss in over a decade [1][2][3][5]. Market analysts attribute the sharp correction to mounting concerns over the profitability of the artificial intelligence (AI) value chain, compounded by aggressive foreign investor sell-offs and the suspension of major corporate share buyback programs [1][2][3][5]. The downturn has raised alarms among global portfolio managers regarding potential slowdowns in export demand and shifting capital flows across East Asian equity markets.
Chaebol Performance Diverges: SK Group Bears the Brunt, LG Shows Resilience
The market rout exposed stark contrasts in performance among South Korea’s chaebols. SK Group experienced the most severe decline, with its market capitalization collapsing by 30.1%, driven primarily by steep losses in SK Hynix (down 28.1%) and SK Square (down 32.0%) as investors questioned the long-term profitability of AI-related infrastructure investments [1][2][3][5]. In absolute terms, SK Group’s valuation shrank by 470.433 trillion won, accounting for nearly 43% of the total market value wiped out across the top ten groups [1][2][3][5]. Samsung Group, while suffering a slightly lower percentage decline of 24.3%, bore the largest absolute loss of approximately 525 trillion won ($396.1 billion), largely due to a 19.6% drop in Samsung Electronics’ valuation [1][2][3][5]. Together, Samsung and SK Group accounted for 90% of the total market capitalization decline among the top ten conglomerates [1][2][3][5]. Conversely, LG Group demonstrated notable resilience, with its market capitalization declining by just 5.3%. Analysts credit this relative stability to gains in LG Energy Solution, which benefited from surging demand for energy storage systems (ESS) tied to AI data center expansion [1][2][3][5].
Export-Oriented Sectors Suffer as Won Strengthens and Global Demand Wavers
Other major chaebols with significant exposure to export-driven industries also faced substantial losses. HD Hyundai Group, whose portfolio includes shipbuilding and industrial machinery, saw its market capitalization decline by 25.6%, while Hanwha Group, a key player in defense and aerospace, experienced a 19.3% drop [1][2][3][5]. Hyundai Motor Group and GS Group followed with declines of 15% and 13%, respectively, as the stronger South Korean won eroded the competitiveness of their overseas revenue streams [1][2][3][5]. The downturn in shipbuilding stocks, in particular, reflected growing concerns over a potential peak-out in global maritime trade demand, further pressuring HD Hyundai’s valuation [1][2][3][5]. Meanwhile, POSCO Group’s market capitalization contracted by 6.4%, a relatively modest decline compared to its peers, supported by steady demand for steel in infrastructure projects despite broader market headwinds [1][2][3][5].
Triggers and Contagion: How AI Profitability Doubts Sparked a Regional Sell-Off
The market correction that began in mid-October 2026 was triggered by a confluence of factors, including the release of U.S. CPI data showing persistent inflation at 3.7% year-on-year, which heightened expectations for further monetary tightening by the Federal Reserve [1][2][3][5]. This macroeconomic backdrop exacerbated existing concerns over the sustainability of AI-related investments, particularly given the substantial debt burdens carried by major tech firms in South Korea’s semiconductor and data center sectors [1][2][3][5]. On October 15, 2026, the Kospi index plunged 7.57% to close at 5,554.22, triggering multiple circuit breakers as foreign investors offloaded a net 3.6243 trillion won ($2.7 billion) in equities [1][2][3][5]. The sell-off quickly spread to regional markets, with Japan’s Nikkei 225 and Taiwan’s TAIEX declining by 4.90% and 3.41%, respectively, underscoring the global nature of the risk-off sentiment [1]. Market participants now warn that the correction may not be contained to equities, with ripple effects potentially impacting South Korea’s currency, bond markets, and real estate sectors in the coming months [alert! ‘analysts cite elevated debt levels and interconnected financial systems as key transmission channels’].