KOSPI Today: What's Driving the Sell-Off?

By Kimi · November 6, 2026 · 10 min read

Key takeaways

The KOSPI closed Friday, Nov. 6, 2026 at 5,059.69, down 324.11 points or 6.02%, after falling 5.28% on Nov. 5.
⚠️ It traded as low as 4,911.28 but did not close below 5,000, despite many morning headlines saying “below 5,000.”
Yonhap and The Korea Herald tie Friday’s fall to Wall Street’s Nov. 5 tech and chip rout, driven by worry that a Democratic Congress could slow AI data center construction.
SK hynix closed down 10.44% and Samsung Electronics down 6.35%; together they account for nearly half of the KOSPI market, per Yonhap.
Trading was halted for 20 minutes from 9:03 a.m. KST, and Korean authorities agreed to waive margin-loan collateral requirements for three months from Nov. 9.
The index is about 44.5% below its June 22 record close but still about 20% above its end-2025 close of 4,214.17.

On Friday, Nov. 6, 2026, South Korea’s KOSPI closed down 324.11 points, or 6.02%, at 5,059.69, its second straight steep loss after a 5.28% fall on Nov. 5. Yonhap and The Korea Herald tie Friday’s drop to a sharp U.S. tech and chip sell-off, driven by worry that a Democratic Congress could slow AI data center construction. The index traded as low as 4,911.28 but did not close below 5,000. Figures are pinned to 4:34 p.m. KST on Nov. 6 (2:34 a.m. ET). Seoul’s regular session is over, and “today” here means that session until the market reopens at 9 a.m. KST Monday, Nov. 9 (7 p.m. ET Sunday, Nov. 8).

Why did the KOSPI fall on Nov. 6?

The most common explanation is that Wall Street’s Nov. 5 rout in AI and chip stocks carried into Seoul, on fear that U.S. election results could slow data center construction. Outlets agree on that core and differ on how much else they add:

Yonhap (closing report): Fear that a Democratic Congress could slow AI data center building. It quotes Daishin Securities analyst Lee Kyoung-min saying concern about tighter data center rules spread across the AI value chain, including chips. He noted that five states that flipped Democratic, including Texas , are top data center locations.
Yonhap (updated News Focus): Quotes Shinhan Financial Investment’s Yoon Chang-yong saying concern over raising funds for AI investment has spread into doubts about recovering money already invested.
The Korea Herald: Points to the overnight U.S. sell-off, when the Philadelphia Semiconductor Index fell 12.25% and the Nasdaq Composite 5.52% amid concern over data center delays.
Korea JoongAng Daily: Quotes the same Daishin analyst with a wider list: Big Tech’s financing burden and doubts about AI profitability, with regulation fears on top.
CNBC (on the U.S. side): Says Democratic wins in the House, the Senate and governorships such as Texas raised traders’ concern about slower data center construction.
Yonhap (opening report only): Adds a rise in oil after Iranian forces said at least five tankers were damaged in the Strait of Hormuz. Yonhap’s closing report does not repeat this, so it reads as a secondary factor.

Yonhap reports that the new Congress takes control in January, and the reports describe worry about what lawmakers might do, not a rule that Congress has passed. See our midterm results page for the race calls. This page takes no view on the election or on data center policy.

Did the KOSPI close below 5,000?

No: it closed at 5,059.69, about 148 points above its 4,911.28 low. Many morning headlines said “below 5,000” because the index traded there during the session. The day opened at 5,263.26, peaked at 5,269.10 and was down 8.52% at 4,924.61 when trading stopped at 9:03 a.m. KST, so the fall was not a straight line from open to close.

Naver’s daily index rows put that in 2026 context:

It was the lowest close since March 31 (5,052.46).
The intraday low was the lowest since Feb. 6 (4,899.30).
The last close under 5,000 was Feb. 2 (4,949.67).

How does Nov. 6 compare with the rest of 2026?

It was a large fall but not the year’s largest: Naver’s rows show 11 steeper one-day drops in 2026. Those include March 4 (down 12.06%), July 28 (down 10.84%) and Oct. 15 (down 7.57%). Together, the Nov. 5 and Nov. 6 sessions took about 11% off the Nov. 4 close of 5,683.80.

The table below shows each session’s close and its percentage change from the session before, from Naver’s rows. The index closed at 5,469.47 on Oct. 26 and then ran up over two sessions, so the Oct. 28 close of 6,012.44 was itself the end of a sharp rise. Yonhap ties that Oct. 28 gain to SK hynix’s record quarterly earnings and added shareholder returns.

Date	Close	Change
Oct. 28	6,012.44	+6.63%
Oct. 29	5,937.66	-1.24%
Oct. 30	5,730.74	-3.48%
Nov. 2	5,859.08	+2.24%
Nov. 3	5,648.79	-3.59%
Nov. 4	5,683.80	+0.62%
Nov. 5	5,383.80	-5.28%
Nov. 6	5,059.69	-6.02%

Did Wall Street’s rout cause both days of losses?

No: Seoul’s Nov. 5 fall came before Wall Street’s Nov. 5 rout, which then fed into Friday’s session. The order matters:

Nov. 4, New York: Broad U.S. indexes rose after the election. JoongAng reports the Dow up 3.03% and the Nasdaq up 1.44%, but the Philadelphia Semiconductor Index down 3.13%.
Nov. 5, Seoul: The KOSPI fell 5.28%. Yonhap ties this to concern over tighter AI data center rules, with chip shares and foreign selling leading the drop.
Nov. 5, New York: Hours after Seoul closed, the S&P 500 fell 4.36% and the Nasdaq 5.52% (Yonhap), and the Dow lost more than 1,800 points, or 3.4% (CNBC). CNBC says the Nasdaq closed more than 10% below its recent high, which it calls correction territory. Nvidia fell 9% and AMD 17%, per CNBC.
Nov. 6, Seoul: The KOSPI opened 2.24% lower, then fell more than 8% within minutes.

The market was also weak before the election. Yonhap tied the Oct. 29 fall to Samsung’s slight earnings miss and its lack of an update on shareholder returns, the Oct. 30 fall to Alphabet’s drop and doubts about returns on AI investment, and the Nov. 3 fall to worry about heavy AI spending.

Which big stocks fell, and who was selling?

Chip heavyweights weighed most on the index and foreign investors were the net sellers, offloading about 2.77 trillion won of KOSPI shares on Nov. 6, per Yonhap. Retail and institutional investors bought a combined net 2.3 trillion won. Naver’s preliminary feed, which was still shifting after the close, splits that into about 1.7 trillion won from institutions and about 500 billion won from retail.

Closing moves on Nov. 6 among the large companies Yonhap named:

SK hynix: down 10.44% to 1,132,000 won
Samsung Electronics: down 6.35% to 188,700 won
Hyundai Motor: down 4.77% to 279,500 won
KB Financial: down 3.82% to 151,000 won
Hanwha Aerospace: down 2.94% to 660,000 won
Samsung SDS: up 6.34% to 218,000 won
Naver: up 2.87% to 190,200 won

Some other KOSPI 200 names fell further. Yonhap’s closing price list has Kumho Petrochemical at 92,500 won, down 19,400, or about 17% by our arithmetic. We are not assigning a cause to those moves.

At 9:25 a.m. KST, just after trading resumed, Yonhap had Samsung down 9.98% and SK hynix down 11.63%. These are snapshots, not session lows. Yonhap notes the pair account for nearly half of the KOSPI market, which is why their moves weigh so heavily on the index. Overnight, JoongAng reports SK hynix’s U.S.-traded ADRs fell 13.4% (more on that listing here ).

Losers outnumbered winners 757 to 131, on volume of 297 million shares worth 27.5 trillion won, per Yonhap. For Nov. 5, the outlets differ slightly on net foreign selling: Yonhap says 3.39 trillion won and JoongAng says 3.43 trillion won.

How did the won, KOSDAQ and Japan do?

All three weakened: the won was quoted at 1,356.6 per dollar at 3:30 p.m. KST, the KOSDAQ fell 5.03% and the Nikkei 225 fell 5.96%.

Won: Quoted at 1,356.6 per dollar at 3:30 p.m. KST, down 14.5 won from 1,342.1 at the same time on Nov. 5, per Yonhap.
KOSDAQ: Closed at 644.27, down 34.14 points, per Naver. It fell 5.11% to 678.41 on Nov. 5, per JoongAng.
Nikkei 225: Closed at 57,434.77, down 3,643.13 points, per Naver.

What is a circuit breaker, and why did it trigger?

A first-stage circuit breaker halts KOSPI trading for 20 minutes when the index stays at least 8% below the prior close for one minute, and it fired at 9:03 a.m. KST on Nov. 6 (7:03 p.m. ET on Nov. 5). It is a result of the fall, not a cause of it.

JoongAng says it was the first since Oct. 15, 16 trading sessions earlier. The outlets count the year’s total differently: Yonhap calls it the tenth this year, and JoongAng calls it the 11th first-level breaker on the main board. JoongAng also reports sell-side sidecars, a five-minute curb on program selling, at 9:06 a.m. on the KOSDAQ and 9:34 a.m. on the KOSPI.

What has the South Korean government done?

Authorities agreed on Nov. 6 to waive collateral requirements on brokerage margin loans for three months starting Monday, Nov. 9, according to Korea JoongAng Daily and Yonhap. Brokerages normally must hold collateral worth at least 140% of the money lent for stock purchases, JoongAng reports. The stated aim is to prevent forced selling that would add pressure on shares.

The decision came at an emergency financial-market meeting that included Finance Minister Lee Hyoung-il, Financial Services Commission Chairman Lee Eog-weon, Financial Supervisory Service Governor Lee Chan-jin and Bank of Korea Senior Deputy Governor Kwon Min-soo. JoongAng reports regulators are also preparing contingency measures to use if volatility worsens, and Yonhap quotes the finance minister saying authorities are “ready to take additional actions” in that case. An earlier Yonhap report gave the waiver’s start only as “later this month,” and we have not seen an official release with the full terms.

Has the KOSPI lost all its 2026 gains?

No: 5,059.69 is still about 20% above the end-2025 close of 4,214.17, but about 44.5% below the record close of 9,114.55 set on June 22. Both base figures are from JoongAng. It is also about 11.7% below the Oct. 30 close and about 15.8% below the Oct. 28 close, by our arithmetic.

What dates are next on the calendar?

The next scheduled item is the U.S. October jobs report at 8:30 a.m. ET on Nov. 6, and Seoul reopens at 9 a.m. KST on Monday, Nov. 9 (7 p.m. ET Sunday, Nov. 8). This is a list of scheduled dates, not a market view, and this report is not investment advice.

Nov. 6, 8:30 a.m. ET: U.S. October jobs report (BLS); not yet out when this was pinned.
Nov. 9: Korea’s margin-loan collateral waiver starts.
Nov. 10, 8:30 a.m. ET: U.S. October CPI (BLS).
Nov. 17, 5 p.m. ET: Nvidia’s third-quarter fiscal 2027 earnings call.
Nov. 19: KOSPI and KOSDAQ trade from 10 a.m. to 4:30 p.m. KST, an hour later than usual, for the college entrance exam (Korea Exchange, via Yonhap).
Nov. 26: Bank of Korea monetary policy meeting.
Dec. 4, 8:30 a.m. ET: U.S. November jobs report (BLS).
Dec. 8-9: Federal Reserve FOMC meeting.
Dec. 10, 8:30 a.m. ET: U.S. November CPI (BLS).

Sources

How we verified this

The closing figures for Nov. 6 (5,059.69, down 324.11, down 6.02%, low 4,911.28, open 5,263.26) rest on Yonhap’s closing story and flashes and on Naver’s KRX-derived daily index rows, read on Nov. 6 at about 07:34 UTC (4:34 p.m. KST, 2:34 a.m. ET). The Korea Herald printed the open as 5,263.63; Yonhap’s market data, JoongAng and Naver agree on 5,263.26, so we use that.

KOSDAQ’s close (644.27, down 5.03%) comes from Naver’s rows, and Korean-language closing headlines from Yonhap and News1, seen in Google News, give the same figures. The Nikkei 225’s close (57,434.77, down 5.96%) comes from Naver’s rows only; we did not see a wire closing story for it. The foreign and combined retail-institution net figures are Yonhap’s. The split between retail and institutions is Naver’s feed, which kept changing after the close, so it is rounded and labeled preliminary. The early-trading moves for Samsung and SK hynix are Yonhap’s 9:25 a.m. KST snapshot, not session lows; we found no exchange figure for either stock’s low. Kumho Petrochemical’s percentage is our arithmetic on Yonhap’s closing price list.

The drivers are attributed outlet by outlet because the framing differs. The oil point appears only in Yonhap’s opening report. The year’s circuit-breaker count differs by outlet (Yonhap tenth, JoongAng 11th) and we report both. On the margin-loan waiver, Korea JoongAng Daily and Yonhap’s updated News Focus both give a three-month period starting Monday, Nov. 9; an earlier Yonhap report said only “later this month.” The 140% figure is JoongAng’s. We did not see a Financial Services Commission or Finance Ministry release.

Comparisons with earlier 2026 sessions, the percentage distances from the record and from end-2025, and the two-session fall are our own arithmetic on Naver’s daily rows, using JoongAng’s 4,214.17 for end-2025 and 9,114.55 for the record close. Calendar dates were read on the BLS (via an archived copy), Federal Reserve, Bank of Korea and Nvidia pages; the Nov. 19 trading hours come from Yonhap’s report of the Korea Exchange statement. All “now” statements are pinned to Nov. 6, 2026, 4:34 p.m. KST, before the U.S. jobs report and before Friday’s U.S. session.