Bank employees work in front of several monitors at the Hana Bank dealing room in Seoul, South Korea on May 12, 2026.
Nurfoto | Nurfoto | getty images
Wall Street tech moves and South Korea’s stock market are becoming increasingly intertwined as artificial intelligence spending ties the fortunes of US technology giants and Korean memory chip makers together.
60 day correlation between Kospi And nasdaq 100 recently climbed to around 0.50, its highest level since 2021, according to data provided by Reliant.
The growing relationship reflects the growing dominance of Samsung Electronics and SK Hynix, which together account for more than half of the Kospi index. Both companies sit at the center of the AI hardware supply chain, providing essential memory chips for data centers operated by US technology giants.
“The correlation has increased since the KOSPI has become a semiconductor index,” Futurum Group analyst Rolf Bulk told CNBC via email.
Samsung and SK Hynix are increasingly relying on the same hyperscaler spending that drives the earnings of U.S. semiconductor and technology companies. Data-center demand has grown from about 40% of global DRAM demand last year to more than half this year, according to Bulk, who expects that share to grow even further. DRAM, or dynamic random-access memory, is used in AI servers.
This gives investors in Asia an early insight into the strength of the global AI business before Wall Street opens.
“Samsung and SK Hynix provide the first liquid market response to the overnight growth impacting global AI demand,” said Jung In Yun, founder of Fibonacci Asset Management. “SK Hynix has become a particularly important barometer due to its exposure to high-bandwidth memory, one of the most critical components in the AI supply chain.”
Recent trading reflects that dynamic. On July 13, the Kospi fell more than 8% due to SK Hynix’s 15% decline and record decline. The Nasdaq 100 also closed down 1.88% on the day. Shares of big technology names fell that day. Micron Technology closed down 4%, Sandisk fell 12%, Intel retreated 6%.
Peter Kim, head of global investment strategy at KB Financial Group, said the Korean memory-chip rally started later than the Nasdaq’s rise because U.S. investors initially focused more on hyperscalers. However, the scale and volatility of the recent rally have led global investors to consider Korea as a harbinger for broader AI trades.
Samsung’s earnings guidance may also provide the first concrete indication on the state of AI demand each quarter. The company typically reports its earnings about two weeks ahead of major U.S. semiconductor companies.
However, analysts cautioned that Korean and US technology stocks are increasingly moving together rather than ahead of the other.
“The fortunes of US tech stocks and Korean tech stocks are increasingly being driven by a common underlying factor, which is sentiment towards the AI hardware business,” said Philip Wool, head of research at Reliant Global Advisors.
When AI-related news comes out when US markets are closed, Samsung and SK Hynix can act as proxies for how investors might react when Wall Street reopens. When developments occur during US trading, Nasdaq similarly provides a preview of the next Korean session.
There are risks in close relationships. Industry veterans said the rising correlation is eroding the diversification benefits investors traditionally seek by holding U.S. and Korean equities.
“Korea no longer offers diversification against US tech. With half the index tied to a cyclical theme, a slowdown in hyperscaler capex will hit the Korean market more than other markets,” Bulk said.
Korean memory stocks are also inherently more volatile than many U.S. chipmakers, with volatility exacerbated by leveraged exchange-traded fund flows, he said.
Wool similarly highlighted that as the AI theme increasingly becomes a major driver of Korean and US technology stocks, investors are losing one of the main reasons for holding on to both markets: geographic diversification.
“When all these markets are essentially being driven by this one big risk factor, you find that you lose the benefit – international diversification – that made you want to invest in geographically disparate markets like the US and Korea in the first place.”
That said, there may be an even bigger difference over time. micronSamsung and SK Hynix currently benefit from similar increases in DRAM prices, but differences in capital spending, product mix and U.S. support for domestic chip production could ultimately differentiate their performance, Kim said.
China’s expansion in memory chips is also another emerging risk, he said. While Chinese manufacturers lag behind their global rivals technologically, their progress has often exceeded investors’ expectations. Shares of chip maker Changxin Technology Group soared 466% on Monday in their debut on Shanghai’s tech-heavy Star Market, making CXMT the most valuable company listed in China.