South Korea’s National Pension Service (NPS), one of the world’s largest public pension funds with approximately $1.22 trillion in assets, is becoming increasingly concentrated in two companies that have come to define both the country’s stock market and its economic outlook: Samsung Electronics and SK Hynix.
The shift is not simply the result of an investment decision. It reflects how artificial intelligence has transformed South Korea’s equity market, making the world’s largest memory-chip makers increasingly difficult for even the country’s biggest institutional investor to avoid.
An analysis by corporate research firm Leaders Index found that the market value of the NPS’s domestic holdings of at least 5% in listed companies reached approximately $336 billion as of July 10, up from about $94 billion at the end of 2024. While the pension fund increased the number of companies in which it owns at least a 5% stake by only eight—to 267 companies from 259—the value of those holdings surged 257.8%, or roughly 3.6 times.
Most of that increase came from one place.
Samsung Electronics and SK Hynix now account for approximately $186 billion of the portfolio, representing 55.5% of its disclosed domestic equity holdings. At the end of 2024, the two companies represented just 25.3%.
The transformation says as much about South Korea’s stock market as it does about the pension fund itself.
Global investors have poured money into semiconductor companies as spending on artificial intelligence infrastructure accelerates. Demand for high-bandwidth memory chips used in AI servers has pushed SK Hynix to record valuations, while Samsung Electronics has benefited from expectations that it will narrow the technology gap in advanced memory and foundry manufacturing.
As those companies became larger, the NPS inevitably became more exposed.
The pension fund did modestly increase its ownership of both companies, raising its Samsung Electronics stake to 7.9% from 7.3% and its SK Hynix holding to 8.1% from 7.6%.
But the bigger story was not additional buying.
The value of the Samsung stake climbed to roughly $95 billion from $17 billion, while the SK Hynix holding jumped to approximately $91 billion from about $7 billion. In other words, market appreciation—not aggressive accumulation—accounts for most of the portfolio’s transformation.
That distinction matters because it highlights the limitations facing large institutional investors.
Unlike hedge funds or actively managed portfolios, public pension funds generally cannot make frequent tactical shifts without disrupting markets or deviating from long-term asset-allocation principles. As market leaders continue to outperform, their weight inside the portfolio naturally expands.
In many respects, the NPS is becoming a mirror of South Korea’s economy.
Information technology and electronics now account for 62% of the pension fund’s major disclosed domestic holdings, more than doubling from 30.3% six months earlier. Holding companies rank a distant second at 11.4%, followed by shipbuilding, defense and industrial machinery at 5.4%.
Other industries have steadily faded in relative importance.
The market value of the fund’s pharmaceutical and biotechnology holdings declined to approximately $7.1 billion, while their portfolio weight dropped from 7.8% to just 2.1%. Food and beverage companies also lost ground as semiconductor stocks absorbed a growing share of investor capital.
The concentration reflects a broader structural shift in South Korea’s equity market.
For decades, Samsung Electronics has dominated the benchmark Kospi index. Now AI is reinforcing that dominance while elevating SK Hynix into an equally influential position. Together, the two companies increasingly determine not only the direction of the stock market but also the composition of institutional portfolios benchmarked against it.
That growing dependence is beginning to raise new questions.
A portfolio in which more than half of the disclosed domestic holdings are concentrated in two semiconductor companies offers significant upside as long as AI investment continues to expand. But it also leaves one of the world’s largest pension funds increasingly tied to a single industry whose fortunes depend on the sustainability of global AI spending, technology cycles and geopolitical stability.
Those concerns have fueled speculation that the NPS could eventually reduce its semiconductor exposure through portfolio rebalancing after a temporary suspension of domestic equity rebalancing expired in June.
The pension fund has pushed back against those expectations.
NPS Chairman Kim Sung-joo recently dismissed concerns that rebalancing would trigger broad selling in the domestic market, saying there is “zero” chance the process would become indiscriminate liquidation. Instead, he described the exercise as routine portfolio management designed to maintain long-term strategic allocations rather than reduce exposure to Korean equities.
For investors, however, the episode highlights something larger than the portfolio of a single institution.
The AI boom is no longer reshaping only technology companies—it is reshaping the structure of capital markets themselves. Just as Nvidia has become an increasingly dominant force in major U.S. equity indices, Samsung Electronics and SK Hynix are becoming indispensable pillars of South Korea’s market.
For now, the National Pension Service appears to be making an enormous bet on semiconductor companies. In reality, it may simply be reflecting the changing shape of the South Korean economy, where AI-related chipmakers have become too large—and too important—to ignore.
