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Kospi Index analysis as Samsung, SK Hynix jumps despite key Ken Griffin warning

Reported by Invezz
Oct 21, 2026· 3 min read
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Key Takeaways
  • • The Kospi Index rose more than 4% on Wednesday to 5,772 points, rebounding from a weekly low of 5,465, as memory chipmakers led the rally.
  • • Samsung Electronics gained 7.3%, SK Hynix rose 8%, and SK Square climbed 7%, tracking a rally in US memory and AI names including Dell and Nvidia, which each gained over 2%.
  • • Billionaire hedge fund manager Ken Griffin said the AI industry is 'certainly in a bubble right now,' while Ray Dalio has also warned of an AI bubble burst; the AI Stock Bubble Index has climbed above 70.
  • • South Korea's headline producer price index eased to 7.7% from 7.9%, and the Bank of Korea's rate decision is due the following day, with most economists expecting rates to hold at 3%.
  • • Technical analysis flags the Kospi as remaining below its 50-day moving average with a small bearish flag, pointing to a possible retest of the 5,272 support level.
Summary
The Kospi Index jumped more than 4% on Wednesday to 5,772 points, recovering from a weekly low of 5,465. The gain mirrored a broader rebound in global equities, with the Dow Jones up 530 points and the S&P 500 up 25 points, according to the report. Japan's Nikkei 225 and Hong Kong's Hang Seng also rose modestly. The rally followed a retreat in bond yields and crude oil prices on hopes of a potential US-Iran deal to end the war, although Brent was still trading at $110 and West Texas Intermediate at $100.

South Korea's largest chip stocks led the advance. Samsung Electronics rose 7.3%, SK Hynix gained 8%, and SK Square climbed 7%. The move coincided with a rally in US memory and AI-linked companies, with Dell and Nvidia each gaining more than 2%.

Concerns about valuations in the AI sector persisted. Billionaire Ken Griffin, whose firm runs one of the largest and most successful hedge funds and is also a major market maker, said the AI industry is 'certainly in a bubble right now.' Ray Dalio, founder of another leading hedge fund, has also warned that the AI bubble will burst, and the AI Stock Bubble Index has risen above 70. The report notes that a burst would weigh on the Kospi given the concentration of its largest constituents in the AI and semiconductor industry.

South Korea's producer price index also supported sentiment. The headline PPI eased to 7.7% from 7.9%, a figure the report characterized as encouraging. The release came a day before the Bank of Korea's interest rate decision. A Reuters poll found most economists expect the central bank to hold rates at 3% after its recent back-to-back hikes. A BNP Paribas analyst said the risks are tilted to the upside, as strong semiconductor-driven growth could spread into domestic demand and create inflationary pressure.

On the technical side, the Kospi was trading at 5,755, just above the key support level of 5,272. The index remains below its 50-day moving average and is forming a small bearish flag pattern, which the report says suggests a possible resumption of the downtrend toward 5,272.

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Sources

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AlphaMaven summarised this story from the reporting below. Each link opens the original article.

Invezz Kospi Index analysis as Samsung, SK Hynix jumps despite key Ken Griffin warning