Why it matters
- South Korea's Kospi fell 2.62% to 6,625.93 on Thursday, Oct. 8, its third straight loss. It is 27.3% below its record close of 9,114.55 on June 22.
- Memory-chip makers have fallen furthest. SK hynix is 42.4% below its June 22 peak close and Samsung Electronics 27.7% below its June 18 high, Yahoo Finance data show.
- Taiwan's Taiex, TSMC and Nvidia closed at one-year highs this week, so the slide is concentrated in memory chips rather than all AI chip stocks.
Analysis: this piece includes our interpretation of the facts reported.
South Korea's Kospi fell 2.62% to 6,625.93 on Thursday, Oct. 8, its third straight loss, Trading Economics said. The index is now 27.3% below its record close of 9,114.55 on June 22, according to Yahoo Finance data, even as Samsung Electronics forecast record quarterly profit.
The index is still up about 57% this year. It closed 2025 at 4,214.17, according to Korea Pro.
How far have Korea's chip stocks fallen?
Memory chipmakers have fallen the most. SK hynix shares closed at 1,681,000 won on Thursday, 42.4% below their June 22 peak close. Samsung Electronics closed at 262,000 won, 27.7% below its June 18 high. Both fell about 2.4% on Thursday, Yahoo Finance data show.
The selloff has spread beyond Seoul, but it is uneven. U.S. chip stocks fell on Thursday after the Financial Times reported that OpenAI's revenue was well below expectations, Trading Economics said. The Philadelphia Semiconductor Index lost 3.39% and the Nasdaq Composite 1.25%.
| Stock or index | Oct. 8 close | Change Thursday | From 1-year high close |
|---|---|---|---|
| Kospi (South Korea) | 6,625.93 | −2.62% | −27.3% (June 22) |
| SK hynix | 1,681,000 won | −2.44% | −42.4% (June 22) |
| Samsung Electronics | 262,000 won | −2.42% | −27.7% (June 18) |
| Micron (U.S.) | $1,035.84 | −4.79% | −14.6% (June 25) |
| Philadelphia Semiconductor Index | 12,623.72 | −3.39% | −13.7% (June 22) |
| Nvidia | $230.48 | −2.94% | −3.7% (Oct. 6) |
| TSMC (Taipei) | NT$2,550 | −1.35% | −1.4% (Oct. 6) |
| Taiex (Taiwan) | 49,313.44 | −0.99% | −1.0% (Oct. 6) |
Source: Yahoo Finance chart data. One-year highs are daily closes; dates in parentheses.
Why are Korean chip stocks falling when profits are at records?
Investors had already priced in a lot. Samsung estimated record third-quarter operating profit of 107.4 trillion won, above forecasts, Trading Economics said, but its shares still fell on Thursday. Trading Economics tied the day's losses to rising global bond yields, inflation worries and Federal Reserve minutes that showed most officials favor another rate hike this year.
The Kospi was also unusually exposed. Samsung and SK hynix made up almost 55% of the index's market value near the June peak, Korea Pro reported in July. Margin loans hit a record 38.63 trillion won, about $26.7 billion, two sessions after the top. Korea Pro said that borrowing magnified an otherwise conventional market correction. On July 28 alone, the Kospi fell 10.84% to 6,023.66, Asia Business Daily reported.
Selling continued after the summer. On Aug. 24, foreign investors sold a net 3.69 trillion won of Korean stocks and the Kospi fell 3.12%, the Korea Times reported. Samsung lost 8.70% that day after a shareholder-return plan left investors waiting for details.
What about the won?
It has gone the other way. The won traded near 1,340 per dollar late Thursday, close to its strongest level in a year of Yahoo Finance data and well up from 1,554.48 on June 8. That is despite a dollar index near a one-year high, as covered in our gold and bitcoin analysis.
For the rest of Asia's Thursday session, see our China reopening analysis. Track U.S., Asian and European indexes on our world markets page.
Sources
- Trading Economics, South Korea stock market (Kospi)
- Trading Economics, United States stock market
- Korea Pro, Why South Korea's KOSPI fell far harder than semiconductor profits justified, July 29, 2026
- Asia Business Daily, KOSPI closes at 6,023.66, down 732.09 points (10.84%), July 28, 2026
- The Korea Times, KOSPI plunges more than 3% as Samsung, SK hynix shares tumble, Aug. 24, 2026
- Yahoo Finance chart data: Kospi (^KS11), Samsung Electronics (005930.KS), SK hynix (000660.KS), Micron (MU), Philadelphia Semiconductor Index (^SOX), Nvidia (NVDA), TSMC (2330.TW), Taiex (^TWII), Nasdaq Composite (^IXIC) and Korean won (KRW=X)