The Kospi extended its run of record highs for a second straight session, easily clearing the 6,400 level. With uncertainty lingering over whether the war in the Middle East will end, the rally has been clear, but caution has also grown.
The gap between the headline index and individual stocks has widened, with gains increasingly concentrated in the market’s two largest semiconductor names, Samsung Electronics and SK Hynix. About 40% of combined buying by institutions and foreign investors has flowed into the two stocks, and the exchange-traded fund market is also being reshaped around semiconductors. Analysts said the concentration could intensify further if a 2x leveraged ETF tied to Samsung Electronics and SK Hynix launches in late May.
Semiconductors drive most of Kospi market-cap gains
22일 Korea Exchange data showed that as of April 21, when the Kospi set a record, Samsung Electronics’ market capitalization stood at 1,280.335 trillion won and SK Hynix’s at 872.348 trillion won. Their weights in the Kospi were 24.45% and 16.66%, respectively, putting their combined share above 40%.
At the end of last year, their weights were 20.41% and 13.63%, meaning they rose 4.04 percentage points and 3.03 percentage points in a little over four months.
From Dec. 30 to April 21, the Kospi’s total market capitalization increased by 1,758 trillion won. Over the same period, Samsung Electronics and SK Hynix together accounted for 967 trillion won of that increase, more than 55%.
Nearly 70% of April foreign net buying went to the two chipmakers
From April 1 to 21, institutions posted net purchases of 5.68 trillion won in the domestic stock market. Samsung Electronics (1.784 trillion won) and SK Hynix (555 billion won) made up 41% of that total.
Foreign investors were even more concentrated. Of their 4.999 trillion won in net buying over the same period, nearly 70% went to Samsung Electronics (2.165 trillion won) and SK Hynix (1.319 trillion won).
The strength in large semiconductor stocks has also widened the gap between the Kospi and the Kosdaq. The Kospi’s market capitalization rose 50% from 3,477.8404 trillion won at the end of last year to 5,236.2070 trillion won, while the Kosdaq grew 29% from 505.9260 trillion won to 653.0304 trillion won.
As of April 21, Kosdaq’s top company by market value, EcoPro, was valued at 22.2270 trillion won, below the level of the Kospi’s 40th-largest company, SK Innovation, at 22.5690 trillion won.
Semiconductor-heavy ETFs gain popularity
The semiconductor tilt is also showing up in ETFs. Asset managers have been rolling out products that hold Samsung Electronics and SK Hynix as core positions, stepping up competition in semiconductor-focused ETFs.
The “RISE Samsung Electronics SK Hynix Bond Mixed 50 ETF,” listed in February, surpassed 1 trillion won in net assets as of April 20, setting the fastest record among domestic bond-mixed ETFs. Samsung Asset Management, Hana Asset Management and Kiwoom Investment Asset Management have launched similar products.
Mirae Asset Management introduced the “TIGER Semiconductor TOP10 Covered Call Active ETF,” which concentrates on semiconductor companies while using a covered-call strategy. Korea Investment Management is running the “ACE AI Semiconductor TOP3+ ETF,” which invests about 75% in three stocks: Samsung Electronics, SK Hynix and Hanmi Semiconductor.
Leveraged ETF launch in May could accelerate inflows
Market participants expect the concentration to deepen, particularly with a leveraged ETF tied to Samsung Electronics and SK Hynix scheduled for late May. Analysts said leveraged products can amplify inflows and outflows as prices move, potentially reinforcing the large-cap-driven trend.
Many in the market expect semiconductor strength to persist, citing improving earnings expectations rather than flows alone. This month, major domestic securities firms raised profit forecasts for the semiconductor sector, projecting continued increases in average selling prices centered on high-bandwidth memory, or HBM.
Kim Dong-won, a researcher at KB Securities, said, “Companies’ adoption rate of AI agents will rapidly expand from 5% in 2025 to around 40% by the end of 2026,” adding that “memory is emerging as a key factor that determines overall AI system performance.”
A financial investment industry official said, “As long as the AI investment cycle continues, it will be difficult for semiconductor-centered fund flows to reverse easily,” and added, “With the expansion of the ETF market, the concentration in large-cap stocks is being structurally reinforced.”
* This article has been translated by AI.
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