KOSPI tumbles 3.88% to 8,304 as tech stocks slide on profit-taking
Synopsis
South Korea's KOSPI briefly cratered nearly 7 percent before recovering to close down 3.88 percent — a circuit breaker was triggered within the first hour. The catalyst: Broadcom's AI revenue miss on Wall Street overnight, which exposed just how much of the recent tech rally in Seoul was built on AI optimism rather than fundamentals.
Key Takeaways
KOSPI fell 334.97 points (3.88%) to 8,304.44 as of 11:20 a.m. on 5 June , after earlier plunging as much as 6.88 percent .
The Korea Exchange triggered a programme-trading suspension for five minutes at 9:08 a.m. after the KOSPI 200 Futures dropped 5 percent .
Samsung Electronics fell 3.56% ; SK hynix sank 5.96% ; LG Electronics shed 8.23% .
Broadcom tumbled more than 12% on Wall Street after its AI revenue outlook disappointed investors.
The Korean won weakened to 1,546.1 per US dollar, down 16.4 won from the previous session.
South Korea's benchmark Korea Composite Stock Price Index (KOSPI) plunged 334.97 points, or 3.88 percent, to 8,304.44 as of 11:20 a.m. local time on Friday, 5 June, as investors locked in profits following a recent tech-driven rally while keeping a close eye on uncertainty surrounding US-Iran peace negotiations. The index had earlier plummeted as much as 6.88 percent before recovering some ground.
Circuit Breaker Triggered
The Korea Exchange suspended programme trading for the KOSPI for five minutes at around 9:08 a.m. — a standard safeguard activated when the KOSPI 200 Futures index drops 5 percent or more for at least one consecutive minute. The session opened 3.44 percent lower before the selloff deepened.
Wall Street's Mixed Close Sets the Tone
Overnight on Wall Street, major indices closed mixed. The Dow Jones Industrial Average gained 1.73 percent, while the S&P 500 added 0.41 percent to close at 7,584.31. The tech-heavy Nasdaq Composite, however, slipped 0.09 percent as declines in artificial intelligence (AI)-related stocks weighed on the index. Broadcom tumbled more than 12 percent after the US chipmaker's quarterly results and its outlook for AI-related revenue fell short of investors' elevated expectations — a signal that rippled across Asian chip stocks.
Large-Cap Stocks Bear the Brunt
In Seoul, most large-cap shares retreated sharply. Market bellwether Samsung Electronics fell 3.56 percent, while rival chipmaker SK hynix sank 5.96 percent. AI investment firm SK Square decreased 5.51 percent, and top automaker Hyundai Motor fell 3.14 percent. LG Electronics shed 8.23 percent, and internet giant Naver decreased 5.98 percent.
Won Weakens Against the Dollar
The Korean won was trading at 1,546.1 won against the US dollar as of 11:20 a.m., down 16.4 won from the previous session, reflecting broader risk-off sentiment across the market. Meanwhile, oil prices retreated after three consecutive sessions of gains, as investor sentiment showed some improvement following reports that Israel had agreed to a conditional ceasefire with Lebanon.
What to Watch
The scale of the intraday recovery — from a 6.88 percent low to a 3.88 percent close — suggests some buyers stepped in at lower levels, but sentiment remains fragile. With Broadcom's earnings miss casting a shadow over global AI valuations and US-Iran negotiations still unresolved, South Korean tech stocks face continued headline risk in the near term.
Point of View
Already navigating a memory cycle recovery, this adds valuation pressure at precisely the wrong moment. The circuit breaker at 9:08 a.m. underscores systemic fragility: when programme trading must be halted within the first hour of a session, the underlying positioning is clearly stretched.
NationPress
21 Jul 2026
Frequently Asked Questions
Why did the KOSPI fall sharply on 5 June?
The KOSPI fell 3.88 percent to 8,304.44 as investors locked in profits from a recent tech-led rally and reacted to Broadcom's disappointing AI revenue outlook on Wall Street. Uncertainty over US-Iran peace negotiations added to the risk-off mood.
Was a circuit breaker triggered on the Seoul stock exchange?
Yes. The Korea Exchange suspended programme trading for five minutes at around 9:08 a.m. after the KOSPI 200 Futures index dropped 5 percent or more for at least one minute — a standard market safeguard.
Which South Korean stocks fell the most?
LG Electronics led declines, shedding 8.23 percent. SK hynix fell 5.96 percent, Naver dropped 5.98 percent, SK Square decreased 5.51 percent, Samsung Electronics fell 3.56 percent, and Hyundai Motor declined 3.14 percent.
How did US markets perform overnight before the Seoul selloff?
US markets closed mixed. The Dow Jones rose 1.73 percent and the S&P 500 gained 0.41 percent to 7,584.31, but the Nasdaq slipped 0.09 percent as AI-related stocks fell. Broadcom tumbled over 12 percent after its quarterly AI revenue outlook missed expectations.
How did the Korean won perform during the selloff?
The Korean won weakened to 1,546.1 won per US dollar as of 11:20 a.m. on 5 June, down 16.4 won from the previous session, reflecting broader risk-off sentiment in the market.
