Bank employees work in front of multiple monitors in the Hana Bank office in Seoul, South Korea, on May 12, 2026.
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The technology moves of Wall Street and South Korea’s stock market are increasingly converging as the use of artificial intelligence consolidates the fortunes of US tech giants and Korean memory chip makers.
Communication within 60 days Kospi again Nasdaq 100 it recently rose to around 0.50, its highest level since 2021, according to data provided by Rayliant.
The growing relationship reflects the increasing dominance of Samsung Electronics and SK Hynix, which together account for more than half of the Kospi index. Both companies sit at the heart of the AI hardware supply chain, supplying the memory chips needed by the data centers used by US tech giants.
“Connectivity has increased because KOSPI has become a semiconductor indicator,” Rolf Bulk, an analyst at Futurum Group, told CNBC in an email.
Samsung and SK Hynix are increasingly reliant on the same hyperscaler that generates revenue for US semiconductor and technology companies. Data center demand has risen from about 40% of global DRAM demand last year to more than half this year, according to Bulk, who expects that share to grow further. DRAM, or dynamic random access memory, is used in AI servers.
That gives investors in Asia an early read on the power of global AI trading before Wall Street opens.
“Samsung and SK Hynix provide the first liquid market in the overnight development market that affects the demand for AI around the world,” said Jung In Yun, founder of Fibonacci Asset Management. “SK Hynix in particular has become an important barometer due to its exposure to high-bandwidth memory, which is one of the most important parts of the AI supply chain.”
Recent trades reflect that volatility. On July 13, the Kospi fell more than 8%, dragged by SK Hynix’s 15% drop and a record fall. The Nasdaq 100 followed suit to finish 1.88% lower for the day. Shares of major tech names fell that day. Micron Technology closed 4% lower, Sandisk shed 12%, Intel retreated 6%.
Peter Kim, head of global investment strategy at KB Financial Group, said the Korean memory-chip rally started later than Nasdaq’s advance because American investors were initially more focused on hyperscalers. The scale and volatility of the latest rally, however, has prompted global investors to treat Korea as a bellwether for the broader AI trade.
Samsung’s earnings guidance may also provide one early signal each quarter on the state of AI demand. The company typically reports earnings about two weeks ahead of major US semiconductor companies.
Analysts cautioned, however, that Korean and US technology stocks are moving in tandem, rather than one continuing to lead the other.
“The fortunes of US tech stocks and Korean tech stocks are increasingly being driven by a common factor, which is sentiment around the AI hardware trade,” said Phillip Wool, head of research at Rayliant Global Advisors.
When AI-related news comes out while US markets are closed, Samsung and SK Hynix can serve as proxies for how investors might respond when Wall Street reopens. If there is a development during US trading, Nasdaq similarly provides a preview of the next Korean session.
Close relationships also have risks. Growing consolidation is eroding the diversification benefits that investors typically seek by holding US and Korean equities, industry veterans echo.
“Korea no longer offers diversification against US technology. With half of the index tied to a single cyclical core, a drop in hyperscaler capex will hit the Korean market harder than most other markets,” said Bulk.
He added that Korean memory stocks are also more volatile in nature than many US chipmakers, with volatility amplified by exchange-traded fund flows.
Wool similarly highlighted that as the AI theme increasingly becomes a dominant driver in both Korean and US tech stocks, investors are losing one of the main reasons to hold both markets: geographic diversification.
“When all these markets are driven by this big risk factor, you find that you’ve lost the benefit – the international diversification – that led you to want exposure to geographically diverse markets like the US and Korea in the first place.”
That said, there may be significant differences over time. MicronSamsung and SK Hynix are currently benefiting from similar increases in DRAM prices, but significant cost differences, product mix and US support for domestic chip production may separate their performance, Kim said.
China’s expansion into memory chips is also another emerging risk, he added. Although Chinese manufacturers still lag behind their global competitors in terms of technology, their progress often exceeds the expectations of investors. Shares of chipmaker Changxin Technology Group soared 466% on Monday in their debut on Shanghai’s tech-heavy STAR Market, making CXMT China’s most valuable listed company.
