Pomegra
Kospi Plunges 5% as Samsung, SK Hynix Sink on AI Fears
Why is the Kospi down today?
Kospi (^KS11) plunged about 5% to near 5,650 on Friday, triggering a sell-side sidecar, after Alphabet's 12.6% plunge on AI profit worries hit Samsung (005930.KS) and SK Hynix (000660.KS).
Key numbers
| Kospi (intraday) | 5,655.41-4.75% (low near 5,599) |
|---|---|
| Samsung Electronics | 220,250 won-5.06% |
| SK Hynix | 1,397,000 won-8.45% |
| Samsung Q3 operating profit | 107.4T wonabout 8.8x year earlier |
| Alphabet shares (Thursday) | $283.82-12.64% |
| Alphabet Q3 free cash flow | -$9.07Bsecond straight deficit |
What happened
Kospi (^KS11) plunged about 5% to near 5,650 on Friday, triggering a sell-side sidecar, after Alphabet's 12.6% plunge on AI profit worries hit Samsung (005930.KS) and SK Hynix (000660.KS). A sidecar is a five-minute pause on automatic sell orders. Samsung had reported a record 107.4 trillion won quarterly profit, nearly nine times a year earlier, but delayed its plan for returning up to 75 trillion won to shareholders until January. Alphabet, Google's parent, burned $9.07 billion in cash last quarter on AI spending.
Why it matters
Kospi, South Korea's main stock index, is closely tied to Samsung and SK Hynix, whose memory chips go into AI data centers. Their drop shows investors now want proof that huge AI spending will turn into real cash, even when profits hit records. A pullback in AI spending could ripple through chip prices, company plans and the savings of people who own these stocks.
Who this affects
- MarketbearishHigh impact
- Korean and global chip investors face sharp, fast losses.
- CompanybearishMedium impact
- Samsung shareholders face losses despite record profit and delayed payouts.
- CompetitorsbearishHigh impact
- SK Hynix fell over 8%; Micron slid about 5% overnight.
- IndustrymixedMedium impact
- Memory makers earn record profits but face AI spending doubts.
Samsung Electronics vs SK Hynix, Micron
| Samsung Electronics005930.KS | 220,250 won | -5.06% |
|---|---|---|
| SK Hynix000660.KS | 1,397,000 won | -8.45% |
| MicronMU | $934.27 | -4.98% (US close, Oct 29) |
As of 2026-10-30
How we got here
Samsung reports record 107.4T won Q3 profit; shares close down 4.13% at 232,000 won.
Alphabet falls 12.64% after $9.07B negative free cash flow; Nasdaq drops about 1.4%.
Kospi falls over 5% in Seoul; sell-side sidecar triggered as chip stocks slide.
What to watch
- Samsung board details how up to 75T won will be returned to shareholders.2027-01
- Whether foreign investors keep selling Korean chip stocks when Seoul reopens.2026-11-02
Educational content only. Not investment advice.
More briefsAll briefs →
10-Year Treasury Yield Tops 5% on Fed Rate-Hike Odds
The 10-year yield (^TNX) rose to 5.05% as the Fed held rates at 3.75–4% and two members voted to raise them.
Chevron Stock Rises 1% Before Q3 Earnings Report
Chevron (CVX) reports before the bell Friday, with analysts expecting profit per share to rise about 160%.
Alnylam Stock Plunges 25% on Weak Demand Outlook
Alnylam (ALNY) fell to $174 as demand for heart drug Amvuttra slowed and Medicare pricing changes loomed