How TSMC and SK Hynix Became AI's Essential Infrastructure

Seven months ago, Germany and France sat comfortably ahead of Taiwan and South Korea in global stock market rankings. Today, that order has been flipped.

Taiwan's stock market is now valued at nearly US$4.3 trillion, surpassing the United Kingdom. South Korea is about US$140 billion away from doing the same. The driving force is not a broadly diversified economic boom. It comes down to three chip companies and the AI gold rush feeding their order books.

For executives across Asia, this reshuffling offers a clear lesson: when hardware becomes the chokepoint for the world's most coveted technology, the countries that make it get repriced accordingly.

The Three Companies Doing the Heavy Lifting

Taiwan Semiconductor Manufacturing Company (TSMC) is the world's largest chip foundry, meaning it physically manufactures the semiconductors designed by companies like Apple, Nvidia, and AMD. Samsung Electronics and SK Hynix are South Korea's leading memory chip makers, producing the high-bandwidth memory that powers AI servers.

All three are key suppliers to Nvidia, the company at the center of the AI infrastructure buildout. When Nvidia needs chips, these are the companies it calls.

TSMC shares have climbed more than 40% this year. Samsung and SK Hynix have each surged more than 80%. TSMC now has a market capitalization of US$2.087 trillion. The Korean pair combined sit at US$1.5 trillion.

To put that in perspective: Europe's largest company, chip-equipment maker ASML, is smaller than TSMC alone. The combined value of all technology stocks in the Stoxx Europe 600 Index stands at about US$1.4 trillion. Asia's top three chip companies are together worth more than the entire European tech sector.

Why This Is More Than a Rally

Stock markets usually track the size of a country's economy, at least loosely. That relationship has broken down here.

The IMF estimates South Korea's GDP at US$1.9 trillion this year and Taiwan's at US$977 billion. Both economies are well below Germany, the UK, and France, each of which has GDP forecasts above US$3 trillion. Yet Taiwan's stock market now outranks the UK's. South Korea is right behind.

Ian Samson, a portfolio manager at Fidelity International, describes what's happening as semiconductors becoming "the new oil," a key input that the entire global economy now runs on. The AI investment wave, he notes, is "price-insensitive," meaning buyers are not shopping around or cutting back based on cost.

Eva Lee, head of Greater China equities at UBS Global Wealth Management, frames the shift as a sector story as much as a country one. "This trend can broadly be viewed as a divergence between technology and non-technology sectors," she said. Europe's markets are heavy on banks and industrial firms. Taiwan and South Korea are heavy on chips.

The macro data backs this up. Taiwan's March export orders surged at the fastest pace in 16 years. South Korea posted more than 40% export growth for the second straight month. Both figures were driven by chip shipments.

The Concentration Problem Investors Are Watching

Here is the uncomfortable arithmetic behind the success story.

Samsung and SK Hynix account for a combined 42% of South Korea's Kospi benchmark. TSMC makes up a similar proportion of Taiwan's Taiex on its own. Two national equity markets now move in near lockstep with the fortunes of a handful of companies.

Some investors have flagged this as a risk. When a single company or pair of companies represents close to half of an entire national stock index, any bad news for those companies becomes a national markets event. It is worth noting that this concentration is not purely a market quirk: it reflects genuine economic dependency. South Korea's Q1 2026 GDP grew 3.6% year-on-year, well above forecasts, but domestic demand remained soft. The economy's health is now a direct function of global AI spending cycles.

Francesco Chan, an emerging markets specialist at JPMorgan Asset Management, offers a more optimistic read. "The AI story in Asia may seem narrow at the index level but is broader across the supply chain," he said. He points to the fact that TSMC's own index weighting has come down from recent highs as other companies like MediaTek and Delta Electronics pick up share. The opportunity, in his view, is widening even if the headline names dominate.

Yi Ping Liao at Franklin Templeton agrees that North Asia has built real structural advantages: "durable advantages in innovation, talent, and manufacturing scale." This is not, she argues, a temporary spike. The data offers partial support. TSMC's Q1 2026 profit surged 58% year-on-year on revenue of US$35.71 billion. SK Hynix operating margins hit 72%, and its entire 2026 HBM supply to Nvidia is sold out. These are not speculative numbers.

But the bears have a point too. TSMC's current price-to-earnings ratio of 35.1 times sits well above its five-year median of 22.55 times. Hyperscalers are projected to spend more than US$600 billion on AI infrastructure in 2026, yet enterprises buying AI services are generating only around US$100 billion in actual AI revenue. That gap is the uncomfortable variable sitting beneath every record quarter.

The Retail Investor Factor

The rally is not purely institutional. South Korea has seen a resurgence of what locals call "ants," a term for mom-and-pop retail traders who tend to move in unison. Taiwan has seen similar growth in retail participation.

Vikas Pershad at M&G Investments described domestic investors as playing an "increasingly important role" across Asia, adding that he sees the market cap gains in Taiwan and South Korea as "justified" on a long-term view.

That retail layer matters because it signals that the repricing of these markets is not being driven solely by foreign capital following an AI theme. Local investors are buying into the story too.

What This Means for the Region

The companies and countries that supply the hardware underlying the AI buildout are being priced like essential infrastructure, not cyclical manufacturers.

For marketing and business leaders in Asia, the implication is straightforward. The region's economic identity is being redefined around technology supply rather than just technology consumption. Understanding where that supply chain runs, and where your own organization sits within it, is now as strategically relevant as understanding consumer trends.

Three companies have pulled Taiwan and South Korea past some of the world's largest economies in market rankings. The question is no longer whether this shift is real. It is how durable the advantage turns out to be.