Index snapshot
The KOSPI closed at 5,593.56, down 1.23% on the day. Its 52-week range runs from 3,079 to 9,385, a span that represents a 205% gap between the low and high. Over the past month the index has fallen 34.01%, while year-to-date it is up 32.41% and over the past 12 months it is higher by 71.87%.
One market, two tempos
Korea’s benchmark has experienced an extraordinary duality: a massive run driven by AI memory demand, followed by a staggering contraction. That same AI memory trade that lifted the market has been at the center of its sharp reversal. The market’s concentration in a narrow set of semiconductor names has created an outcome where index-level performance looks more like the behavior of a single speculative equity than a G20 nation’s main market barometer.
Who moves the market
Samsung Electronics (005930) and SK Hynix (000660) together make up more than half of the KOSPI’s weight. That concentration means that large moves in memory chip makers translate quickly to index-level volatility. Samsung shares were quoted at ₩207,000 with intraday and recent performance showing -0.72% on the day and -23.33% over one month, while SK Hynix was quoted at ₩1,322,000, down -5.64% for the week and -31.11% over one month. Over a longer horizon, Samsung’s one-year gain is listed at +185.12% and SK Hynix’s at +401.71% even as both have suffered steep monthly declines.
Corporate results that confound market moves
In Q2 2026 SK Hynix reported revenue of ₩79.32 trillion, a year-on-year increase of 257%, and operating profit of ₩60.54 trillion, producing an operating margin of 76%. Despite those results, the stock fell 8.98% on the day the results were published. This behavior illustrates a ‘‘buy the rumor, sell the news’’ dynamic taken to an extreme: the market had priced in near-perfection, and delivering the expected outcome did not generate further upside.
Valuation versus volatility
Even amid the AI boom, both Samsung and SK Hynix are trading at price-to-earnings ratios below five times. That valuation level is striking given the reported 76% operating margins and full order books through 2026. Analysts at Meritz Securities, represented by Kim Sunwoo, estimate DRAM suppliers are fulfilling 75-80% of market demand currently, with the possibility that fulfillment could deteriorate to around 60% by 2027. SK Hynix’s CEO has described 2027 as possibly "the worst supply shortage in global memory industry history." The juxtaposition is clear: a structurally bullish supply-demand outlook and exceptional corporate profitability on one hand, and rapidly falling share prices on the other.
Leverage as an accelerant
Market structure has intensified the swings. A Hong Kong-listed 2x SK Hynix leveraged fund expanded roughly twentyfold to $7.78 billion in assets since early 2026, making it the largest single-stock leveraged fund globally. At the same time, Korean retail investors held ₩34.37 trillion in margin loans as of mid-July, a decline from a June record of ₩38.6 trillion but still a very large amount. As regulators and investors respond, forced selling tied to margin calls and leveraged ETF redemptions has been a central driver of the near-term downward pressure.
The finance ministry moved to tighten rules on single-stock leveraged ETFs, raising trading costs and tripling the minimum cash balance required to trade these products to ₩30 million from August 5, 2026. That forced deleveraging process — which involves liquidation of positions as margin and leverage are cut — is an important proximate cause of recent selling.
Macro conditions are mixed but resilient
Outside of chip-related volatility, Korea’s economic data shows resilience. Q2 2026 GDP grew 3.7% year-on-year, above the 3.5% forecast, supported by semiconductor exports. The Korean won strengthened, with USD/KRW reaching a 2.5-month high of 1,466.9 at one point, reflecting capital inflows tied to economic outperformance. That strength raises the possibility of further Bank of Korea tightening - an August 2026 meeting could produce another 25 basis point increase in policy rates, which would exert additional pressure on equities.
Other macro risk factors also affect market sentiment. Escalating tensions in the Middle East have pushed U.S. Treasury yields higher, creating broader rate-sensitive headwinds across growth and technology-linked stocks. Separately, diplomatic engagement at the presidential level yielded major long-term memory chip supply agreements with U.S. technology companies following a visit to San Francisco, reinforcing the link between policy and commercial arrangements in the sector.
Broader Korean economy and corporate themes
Beyond semiconductors, other sectors are drawing attention. Shipbuilding has re-emerged as a significant theme: analysts at CLSA maintain a high-conviction Outperform rating on HD Korea Shipbuilding with a target price of ₩990,000. The sector stands to benefit from LNG infrastructure demand, and South Korea is reviewing a $19.8 billion Texas LNG power plant investment as part of a Korea-U.S. bilateral trade commitment. Meanwhile, Samsung C&T reported Q2 operating profit up ₩279 billion year-on-year, driven by Hi-Tech semiconductor fabrication construction, but cautioned that trading earnings may moderate in Q3, reflecting uneven near-term earnings visibility across related suppliers and contractors.
Bull and bear frameworks for investors
Supporters of a bullish stance point to several factors: sub-5x P/E valuations on market-leading AI infrastructure suppliers, extraordinarily high operating margins, sold-out capacity through 2026, and the prospect of deepening memory supply shortfalls into 2027 as AI capex ramps globally. Large increases in AI spending by major tech companies have been cited as part of the demand story. Some institutions still see upside in emerging market indices that include Korea, suggesting the derating may represent an entry point.
On the downside, some large sell-side firms have reduced their allocation to Korea, noting that the rally had been driven almost entirely by AI-linked stocks. The forced unwinding of leveraged ETF positions is incomplete — a substantial portion of retail margin loans remains in the system — and a potential Bank of Korea rate hike could create additional equity market stress. Global semiconductor indexes have also corrected, with the PHLX Semiconductor index down sharply in July, reinforcing that Korea’s sell-off is happening in a broader sectoral corrective phase. Market commentary from other brokers highlights that investors are increasingly valuing AI investments in light of funding costs rather than only long-term growth potential.
Conclusion - where things stand
Korean markets are undergoing a sharp repricing, not a fundamental collapse. The AI memory thesis that powered the rally remains intact on the supply-demand and corporate-profitability metrics presented, but what is changing is the speculative overlay: large leveraged positions, elevated margin debt and option positions that had priced in uninterrupted upside. The ongoing deleveraging cycle combined with the possibility of higher domestic interest rates and broader risk-off conditions indicate that volatility may continue in the near term. For investors with a 12 to 24 month horizon, the combination of very low P/E multiples on dominant AI infrastructure suppliers and warnings from company leadership about potentially extreme supply shortages presents a high-conviction, if high-volatility, investment scenario.
Key points
- KOSPI moved from +71.87% over the past year to -34.01% in one month, driven by AI memory chip names concentrated in two large companies.
- Samsung Electronics (005930) and SK Hynix (000660) together exceed 50% of KOSPI weight, amplifying index-level moves from single-stock volatility.
- Forced deleveraging in single-stock leveraged ETFs and substantial retail margin debt have materially intensified the sell-off even as corporate profitability and demand fundamentals for memory remain strong.
Risks and uncertainties
- Ongoing forced selling tied to leveraged ETFs and remaining retail margin loans could prolong and deepen market declines, particularly in semiconductor-related equities.
- A potential Bank of Korea interest rate hike in August 2026 would add further pressure on equities, especially on rate-sensitive growth and technology names.
- Global risk-off, including higher U.S. Treasury yields driven by geopolitical tensions, can weaken demand for risk assets and exacerbate equity corrections.