KOSPI Surges to Record High as SK Hynix Earnings Fuel Tech Rally
The South Korean benchmark index, KOSPI (^KS11), reached an unprecedented milestone on Thursday, April 23, 2026, closing at a new record high of 6,475.81. The market was propelled by a significant rally in semiconductor stocks following a stellar earnings report from SK Hynix, which has solidified its position as a global leader in AI memory technology. Conversely, the junior KOSDAQ (^KQ11) experienced a slight pullback as investors locked in profits from the mid-cap sector.
Market Performance Overview
On April 23, the KOSPI closed at 6,475.81, marking an increase of 57.88 points (+0.90%) from the previous session. The index hit an intra-day high of 6,557.76 before settling. Trading volume remained robust, with over 1 billion shares changing hands.
The KOSDAQ index closed at 1,174.31, declining by 6.81 points (-0.58%). The divergence between the two indices reflects a clear rotation of capital into large-cap tech heavyweights, while the secondary market faced pressure from retail-heavy selling.
The Chipmaker Catalyst: SK Hynix Earnings
The primary driver of today’s market euphoria was SK Hynix (000660), which reported record-breaking quarterly profits for Q1 2026. The chipmaker’s stock price touched new highs as demand for high-bandwidth memory (HBM) continues to outpace supply. Samsung Electronics (005930) also benefited from the positive sentiment, contributing significantly to the KOSPI’s upside.
Market analysts note that the “K-Chip” rally is entering a new phase of valuation, supported by sustained AI infrastructure spending globally. The successful navigation of geopolitical risks, including recent maritime tensions, has also bolstered investor confidence in the resilience of Korea’s export-driven economy.
Top Market Movers
| Ticker | Company | Close (KRW) | Change (%) | Note |
|---|---|---|---|---|
| 000660 | SK Hynix | 1,245,000 | +4.2% | Record Q1 Earnings |
| 006400 | Samsung SDI | 582,000 | +3.1% | Mercedes-Benz Supply Deal |
| 012450 | Hanwha Aerospace | 298,000 | +2.7% | Defense Export Growth |
| 068270 | Celltrion | 189,500 | -1.2% | Profit-taking |
| 247540 | EcoPro BM | 241,000 | -2.5% | KOSDAQ Weakness |
Investor Flow and Foreign Participation
The day saw mixed behavior among investor groups. Individual (retail) investors were the primary buyers on the KOSPI, injecting a net 451.4 billion KRW. Meanwhile, foreign investors recorded a slight net sell of 49.9 billion KRW, and institutions offloaded 329.6 billion KRW. This suggests that while retail enthusiasm is at an all-time high, institutional players are maintaining a more cautious stance near the record peak.
On the KOSDAQ, all major groups except individuals were net sellers, contributing to the index’s decline. Foreigners sold a net 146.8 billion KRW on the junior exchange.
Conclusion
As the KOSPI continues to chart new territory, the focus remains squarely on the earnings performance of large-cap tech stocks. Investors are encouraged to monitor the upcoming earnings calls from other major constituents to gauge the sustainability of this rally. For more detailed analysis on Korean equities, visit kstocks.net.
Data Source: Naver Finance, Korea Exchange (KRX), Bank of Korea (BOK).
Disclaimer: This article is for informational purposes only and does not constitute financial advice. Investing in the stock market involves risk. Consult with a professional advisor before making any investment decisions.
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.
Korean blog: blog.naver.com/taximum | Contact: golchoa@gmail.com