The artificial intelligence boom is transforming global financial markets, and nowhere is that more visible than in Taiwan and South Korea, where stock indexes have surged to historic highs on the back of explosive demand for advanced semiconductors and AI hardware.

But beneath the record-breaking rallies lies a growing concern among investors and analysts: Asia’s hottest stock markets are becoming increasingly dependent on just a handful of trillion-dollar technology companies.

This year, South Korea’s Kospi index has climbed more than 80%, repeatedly setting fresh records as global investors poured money into companies tied to artificial intelligence infrastructure, memory chips, and high-performance computing. Taiwan’s Taiex index has followed a similar trajectory, driven overwhelmingly by semiconductor-related stocks at the center of the global AI race.

According to strategists, the current rally is being powered less by broad economic strength and more by a concentrated wave of investor enthusiasm surrounding AI-related hardware manufacturers.

“In a word, it’s the AI hardware theme that’s clearly propelling things,” said Tim Moe, chief Asia-Pacific equity strategist at Goldman Sachs.

The numbers illustrate just how deeply both markets are tied to the artificial intelligence boom.

Taiwan is now estimated to have more than 80% exposure to AI-related revenue streams, while South Korea stands near 60%, according to Goldman Sachs estimates. The rapid expansion of AI data centers, cloud computing infrastructure, and generative AI systems has triggered unprecedented demand for advanced semiconductors, memory chips, and server hardware.

At the center of Taiwan’s rally is Taiwan Semiconductor Manufacturing Company, widely known as TSMC. With a market value approaching 58 trillion Taiwan dollars, or roughly $1.85 trillion, the chipmaking giant now accounts for more than 40% of Taiwan’s benchmark Taiex index.

In South Korea, the concentration is similarly striking. Samsung Electronics and SK Hynix together represented a record 42.2% of the Kospi index in May, according to estimates from Manulife Investment Management.

Samsung Electronics alone recently surpassed a $1 trillion market capitalization as investors aggressively chased AI-linked technology stocks.

The result is a market environment where benchmark gains increasingly reflect the earnings power of a narrow group of semiconductor exporters rather than the overall strength of domestic economies.

Analysts warn that this level of concentration creates significant long-term risks.

A slowdown in AI infrastructure spending, geopolitical tensions involving Asia, supply chain disruptions, or even shifts in technology architecture could trigger sharp corrections across markets that have become heavily reliant on a single investment narrative.

“There certainly is risk with market concentration,” Moe said, pointing to vulnerabilities including supply chain interruptions, political backlash against AI infrastructure expansion, financial-market stress, and emerging technological disruption from next-generation chip designs.

One major concern involves the fragility of the semiconductor supply chain itself.

Taiwan and South Korea sit at the heart of an extraordinarily complex manufacturing ecosystem dependent on specialized materials, chemicals, advanced gases, and photoresists used in semiconductor production. Any disruption to global shipping lanes, regional stability, or industrial supply chains could quickly impact production capacity.

“If you just can’t get them, and therefore you have to stop your production, it would not take a genius to think that the stocks would correct,” Moe said.

The risks are not limited to technology.

Both Taiwan and South Korea are major energy importers, meaning rising oil prices linked to geopolitical tensions in the Middle East could pressure their economies by increasing manufacturing costs, weakening purchasing power, and reducing export competitiveness.

Jamie Mills O’Brien, investment director at Aberdeen Investments, noted that both economies remain highly exposed to energy price volatility at a time when global crude prices are climbing sharply due to tensions involving Iran.

At the same time, investor expectations surrounding AI growth have become increasingly aggressive.

Goldman Sachs estimates that South Korean corporate earnings growth could surge by as much as 300% this year, fueled largely by semiconductor demand. That explosive growth has pushed valuations significantly higher and increased the risk of market volatility if earnings fail to meet expectations.

According to Mixo Das, head of Korea and Taiwan equity strategy at JPMorgan, both markets have historically reflected global export demand more than domestic consumption trends.

“Korea and Taiwan equity markets have always been more a reflection of global demand,” Das said. “It is simply that global demand has become very concentrated in AI at present.”

Still, strategists argue there are important differences between the two economies.

South Korea’s stock market remains somewhat broader and more diversified despite the dominance of chipmakers. Investors have also poured money into sectors such as shipbuilding, defense manufacturing, power infrastructure, entertainment exports, and the rapidly growing “K-culture” industry.

Moe said South Korea’s rally therefore reflects a wider industrial base and stronger alignment with the broader domestic economy.

“The market is actually deeper and broader and has more opportunities than just the superstar memory stocks,” he said.

Taiwan, however, is increasingly viewed as more dependent on a single corporate giant and the global semiconductor cycle.

UOB chief investment officer Qi Wang warned that Taiwan’s growing reliance on TSMC could create structural imbalances across both the economy and financial markets.

“Some people say Taiwan is just a one-trick pony. That’s just TSMC,” Wang said. “Longer term, it does increase the concentration risk for both the economy and the stock market.”

Taiwanese regulators recently relaxed rules limiting how much domestic investment funds can allocate to a single company, a move widely interpreted as supportive of TSMC. Wang estimates the policy change could direct between $30 billion and $40 billion into the chipmaker alone, potentially increasing concentration even further.

Some market observers argue the risks are overstated because semiconductor ecosystems are far more complex than commodity-dependent economies built around a single resource or product.

However, recent global examples highlight how quickly concentrated markets can reverse course.

Last year, Denmark’s stock market struggled heavily as investor enthusiasm surrounding Novo Nordisk weakened amid concerns about slowing demand for obesity drugs. Similarly, Saudi Arabia faced pressure when lower oil prices weighed on the heavily energy-dependent market dominated by Saudi Aramco.

The lesson, analysts say, is that concentration can amplify gains during bull markets — but it can also intensify losses once sentiment changes.

Florian Weidinger, CEO of Santa Lucia Asset Management, warned that many global investors seeking diversification may unknowingly be doubling their exposure to the same AI trade.

By simultaneously investing in U.S. technology giants and Asian semiconductor-heavy indexes, investors may actually be concentrating risk rather than spreading it.

“If that were to break,” Weidinger said, “a lot of allocators will wake up with double risk.”

As artificial intelligence continues reshaping global capital markets, Taiwan and South Korea remain among the clearest examples of how transformative — and potentially fragile — the AI investment boom has become.