MKTMarkets NO. ---
KOSPI Gains 3.25% in Week to Oct 30, 2026 on SK Hynix Record Profit
Seoul's main index closed above 6,000 on Wednesday after SK hynix posted record results and a payout plan of more than 100 trillion won, then slid on Friday as weak US tech earnings revived AI spending doubts.
Key takeaways
- The KOSPI rose 180.44 points, or 3.25%, in the week to Friday, October 30, 2026, closing at 5,730.74 at the Korea Exchange close (06:30 UTC), against 5,550.30 a week earlier.
- The KOSDAQ fell 3.63% over the week to 724.38, so the gain was limited to the main board's biggest chip names.
- SK hynix gained 11.04% over the week to 1,418,000 won after record third-quarter results. Samsung Electronics added 4.41% to 225,000 won.
- The KOSPI closed above 6,000 on Wednesday, October 28, at 6,012.44 after a 6.63% jump. It then gave back ground on Thursday and fell 3.48% on Friday as weak US tech earnings revived doubts about AI spending.
- The won weakened 0.73% against the dollar over the week, to 1,334.3 per dollar at 15:30 KST (06:30 UTC) on Friday, according to Yonhap via Korea JoongAng Daily and The Korea Times.
Week in review
The KOSPI ended the week to October 30, 2026 higher, but the swings were large. Chipmaker earnings pushed the index above 6,000 midweek, and then a US tech sell-off cut the gain on Friday. For other markets in the region, see Asian and global markets today. Last week's moves are covered in our KOSPI weekly brief for October 23.
| Instrument | Prior week close (Fri) | Week close (Fri) | Weekly change | % change | Week high / low | As of (UTC) | Source |
|---|---|---|---|---|---|---|---|
| KOSPI | 5,550.30 | 5,730.74 | +180.44 | +3.25% | 6,100.11 / 5,455.11 | 2026-10-30 06:30 | Investing.com (KRX data); Seoul Economic Daily; The Korea Times |
| KOSDAQ | 751.69 | 724.38 | −27.31 | −3.63% | 773.28 / 717.27 | 2026-10-30 06:30 | Investing.com (KRX data); The Korea Times |
| USD/KRW (won per dollar, 15:30 KST) | 1,324.60 | 1,334.30 | +9.70 | +0.73% | n/a | 2026-10-30 06:30 | Yonhap via Korea JoongAng Daily; The Korea Times |
| Samsung Electronics (won) | 215,500 | 225,000 | +9,500 | +4.41% | 249,000 / 211,500 | 2026-10-30 06:30 | Investing.com; Korea JoongAng Daily |
| SK hynix (won) | 1,277,000 | 1,418,000 | +141,000 | +11.04% | 1,587,000 / 1,267,000 | 2026-10-30 06:30 | Investing.com; Korea JoongAng Daily |
KRX closes at 15:30 KST (06:30 UTC). The won figures are Seoul's 15:30 KST quotes reported by Yonhap. Reports for midweek sessions did not give consistent figures, so the weekly high and low for the won are not shown. A higher USD/KRW means a weaker won.
| Day | KOSPI close | Change | Change % | KOSDAQ close | Change % | As of (UTC) |
|---|---|---|---|---|---|---|
| Mon, Oct 26 | 5,469.47 | −80.83 | −1.46% | 727.21 | −3.26% | 2026-10-26 06:30 |
| Tue, Oct 27 | 5,638.34 | +168.87 | +3.09% | 743.83 | +2.29% | 2026-10-27 06:30 |
| Wed, Oct 28 | 6,012.44 | +374.10 | +6.63% | 771.28 | +3.69% | 2026-10-28 06:30 |
| Thu, Oct 29 | 5,937.66 | −74.78 | −1.24% | 753.23 | −2.34% | 2026-10-29 06:30 |
| Fri, Oct 30 | 5,730.74 | −206.92 | −3.48% | 724.38 | −3.83% | 2026-10-30 06:30 |
Source: Investing.com historical data, checked against closing reports from Yonhap (via Korea JoongAng Daily), Seoul Economic Daily and The Korea Times.
Day by day
- Monday, Oct 26: The KOSPI fell 1.46% to 5,469.47. Investors waited for chip earnings, and Wall Street had closed lower on Friday. Foreigners sold a net 695.5 billion won, according to Yonhap via Korea JoongAng Daily.
- Tuesday, Oct 27: The index rose 3.09%. A buy-side sidecar, a five-minute pause in program buy orders, was triggered at 10:13 KST. Yonhap linked the rally to renewed AI optimism, including Anthropic's US IPO filing, lower oil prices and reports of Qatari mediation between Iran and the US. Foreigners bought a net 592.97 billion won. The Bank of Korea said the economy grew 1.0% quarter on quarter in the third quarter, The Korea Times reported.
- Wednesday, Oct 28: The KOSPI jumped 6.63% to 6,012.44, with a second straight buy-side sidecar. SK hynix rose 10.89% to 1,487,000 won after record quarterly results and a 2026 shareholder return program of more than 100 trillion won. Samsung gained 9.01% to 242,000 won. Foreigners bought a net 815.83 billion won, and individuals sold 1.8 trillion won.
- Thursday, Oct 29: The index reached 6,100.11 during the session, then closed 1.24% lower. Samsung fell 4.13% to 232,000 won after its results, and LG Energy Solution dropped 8.6% after LG Chem decided to sell a large stake.
- Friday, Oct 30: The KOSPI fell 3.48%, and a sell-side sidecar was triggered at about 10:05 KST, the first in 11 sessions. SK hynix lost 7.08%. Foreigners sold a net 1.62 trillion won, while institutions and individuals bought, according to Yonhap via Korea JoongAng Daily.
What drove it
Chip earnings and shareholder returns
Samsung Electronics and SK hynix carry a large weight in the KOSPI, so their results drove the week. SK hynix reported record third-quarter revenue and operating profit, plus a 2026 shareholder return program of more than 100 trillion won ($75.3 billion). Lee Jae-won of Yuanta Securities said the company "demonstrated that strong demand for AI chips can translate into solid operating profits and shareholder returns," according to Yonhap via Korea JoongAng Daily. For details, see our report on SK hynix's record profit.
Samsung's results drew a different reaction. Operating profit reached a record 107.44 trillion won, up 783.1% from a year earlier, on revenue of 195.3 trillion won. Yonhap reported that the figures slightly missed analyst expectations. Lee Kyung-min of Daishin Securities said investor sentiment "weakened as the company did not present a detailed shareholder-return plan."
US tech earnings and AI spending
Friday's drop followed a weak night on Wall Street. The Nasdaq Composite fell 1.38% and Alphabet 12.64%, The Korea Times reported, after Alphabet and Amazon results raised questions about returns on AI infrastructure spending. Kang Jin-hyuk of Shinhan Securities told the paper that "successive earnings disappointments from big tech companies and chipmakers sparked a sell-off across the AI value chain." Local earnings misses added to the pressure: Kia fell 11.73% and Hanwha Aerospace 8.42% on Friday, according to Yonhap via Korea JoongAng Daily.
Macro data and the economy
Tuesday's GDP release showed growth of 1.0% quarter on quarter, above the Bank of Korea's own 0.3% projection. The Korea Times reported that exports rose 2.3% on semiconductors and electrical equipment. The paper also reported that the BoK plans to publish a revised annual forecast in November and is likely to raise it from 3.3%. See our Q3 GDP report.
Foreign flows and the won
Foreign investors bought from Tuesday to Thursday and sold on Monday and Friday. Friday's selling was the largest of the week. Retail investors were net sellers on Tuesday and Wednesday, when foreigners and institutions bought chip stocks, according to Yonhap via Korea JoongAng Daily. The won weakened slightly over the week even though exports were strong.
Political & policy watch
Bank of Korea. The base rate stays at 3.00% after the October 22 decision. In its statement, the board said it would keep responding until it is confident that inflation will settle at its target.
US Federal Reserve. The Fed kept its benchmark range at 3.75% to 4.00%, Yonhap reported on October 29. The KOSPI opened slightly higher on the news.
Corporate governance. Shareholder returns were in focus again this week. Investors compared SK hynix's stated program with Samsung's, which lacked detail. Last week, regulators said an overseas Solidigm listing would fall under the rules on duplicate listings.
Middle East. Hopes for Qatari mediation involving Iran and the US helped Tuesday's rally, according to Yonhap. No agreement had been reported by Friday's close.
What to watch next
- Early November: October trade data from Korea Customs Service and the trade ministry, a key read on chip shipments.
- Early November: October consumer prices from Statistics Korea, one of the inputs the BoK board named.
- November 3: US midterm elections.
- November: the Bank of Korea's revised economic outlook.
- November 26: the next Bank of Korea rate decision.
Risk checklist for readers
- Concentration. Two chipmakers drove most of this week's moves. The KOSPI can behave like a single-sector index.
- Earnings reactions differ. Record profits do not guarantee a share price gain. Expectations and shareholder-return details also matter.
- Overnight links. Seoul trades after the US close, so US tech earnings often set the morning tone.
- Flow data vary. Different outlets report different investor-flow figures depending on the data cut. Check KRX releases.
- Currency effects. A weaker won lowers dollar returns for foreign holders but can raise exporters' earnings in won.
- Trading curbs. Sidecars pause program orders for five minutes. They signal sharp moves in futures but do not stop regular trading.
Frequently asked questions
Why did the KOSPI rise in the week to October 30, 2026?
SK hynix reported record third-quarter results and a 2026 shareholder return program of more than 100 trillion won, which lifted chip stocks and pushed the KOSPI to 6,012.44 on October 28. A 3.48% fall on October 30, after weak US tech earnings, trimmed the weekly gain to 3.25%.
What is a sidecar on the Korea Exchange?
A sidecar is a five-minute pause in program trading orders. On the KOSPI market it is triggered when KOSPI 200 futures move 5% or more and the move lasts for at least one minute. In the week to October 30, 2026, buy-side sidecars were triggered on October 27 and 28, and a sell-side sidecar on October 30.
Why did the KOSDAQ fall while the KOSPI rose?
The week's gains were concentrated in large chipmakers such as SK hynix and Samsung Electronics, which trade on the KOSPI. The KOSDAQ lists smaller growth companies in technology, biotech and batteries, and it fell 3.63% over the week.
This article is for information only and is not investment advice.
