How did Samsung Electronics and SK hynix perform during the KOSPI sell-off?

Samsung Electronics fell 2.98 percent to close at 211,500 won, and SK hynix dropped 4.23 percent to 1.22 million won. SK Square declined 5 percent, while Samsung Electro-Mechanics lost 1.28 percent.

What were foreign investors, institutions and individual investors doing during the stock-market decline?

Foreign investors sold a net 535.4 billion won and institutions sold 1 trillion won. Individual investors took the opposite position, buying a net 900 billion won as decliners outnumbered advancers 771 to 117.

Seoul stocks slide nearly 4% on AI jitters, unrest in France

Q: Why did the KOSPI fall nearly 4 percent on Tuesday?

Investors took profits after recent gains in major chip shares, while concerns about credit risks and profitability surrounding AI investment remained unresolved. Escalating protests in France also reduced appetite for risky assets.

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Summary

Korean shares plunged in Seoul Tuesday as investors took profits in major chip stocks amid persistent AI value-chain concerns and escalating protests in France. The KOSPI fell 215.27 points, or 3.73 percent, to 5,552.74, while the Korean won strengthened against the U.S. dollar. Foreigners and institutions were net sellers, and technology shares led the decline.

Key Facts

Trade volume totaled 259.75 million shares worth 16 trillion won, with 771 declining stocks versus 117 advancing stocks.
Foreigners sold a net 535.4 billion won and institutions sold 1 trillion won, while individual investors bought a net 900 billion won.
Samsung Electronics fell 2.98 percent to 211,500 won, while SK hynix declined 4.23 percent to 1.22 million won.
The Korean won was quoted at 1,328.1 won per U.S. dollar, up 2.2 won from the previous stock trading session.
The three-year Treasury yield fell 3.7 basis points to 3.840 percent, while the five-year government bond yield declined 2.4 basis points to 3.990 percent.

By Yonhap

Published Oct 20, 2026 9:25 am KST
Updated Oct 20, 2026 4:33 pm KST

The benchmark KOSPI is displayed at Hana Bank's dealing room in Seoul, Tuesday. Yonhap

Korean shares plunged by nearly 4 percent Tuesday, as investors attempted to cash in recent gains in major chip shares amid persistent concerns over the artificial intelligence (AI) value chain. The Korean won was trading higher against the U.S. dollar.

The benchmark Korea Composite Stock Price Index (KOSPI) fell 215.27 points, or 3.73 percent, to 5,552.74 after declining as low as 5,493.24.

The index opened 0.6 percent lower and extended its losses amid deepening woes over AI-related sectors as well as escalating protests in France, which sharply reduced appetite for risky assets.

The KOSPI had risen for two consecutive sessions after a sharp sell-off fueled by concerns over AI-related investments. It had plunged by around 21 percent over seven trading sessions from Oct. 6 through Thursday.

Overnight, U.S. stocks ended mixed as technology shares rebounded from their steepest weekly drop since June.

"Concerns over credit risks and profitability surrounding AI investment have yet to be fully resolved, limiting the sustainability of the rebound," said Lee Kyoung-min, an analyst at Daishin Securities. "Profit-taking emerged following the previous session's gains, sending the market back into negative territory."

Trade volume was light at 259.75 million shares worth 16 trillion won ($12.97 billion), with decliners far outnumbering advancers 771 to 117.

Foreigners and institutions sold a net 535.4 billion won and 1 trillion won, respectively, while individuals bought a net 900 billion won.

Market heavyweights fell across the board, led by a sharp sell-off in technology shares.

Market bellwether Samsung Electronics fell 2.98 percent to close at 211,500 won, while rival chipmaker SK hynix declined 4.23 percent to 1.22 million won, heading for its lowest close since April.

SK Square, the parent firm of SK hynix, dipped 5 percent to 741,000 won, while Samsung Electro-Mechanics, an electronics component affiliate of Samsung Electronics, went down 1.28 percent to 1.16 million won.

The Korean won was quoted at 1,328.1 won against the U.S. dollar as of 3:30 p.m., up 2.2 won from the previous stock trading session's close.

Bond prices, which move inversely to yields, closed higher. The yield on three-year Treasurys lost 3.7 basis points to 3.840, and the return on the benchmark five-year government bonds went down 2.4 points to 3,990.

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