Seoul stocks suffer steepest fall in history over widening Iran conflict

A stock ticker at Hana Bank headquarters in central Seoul shows the benchmark KOSPI closing at 5,093.54 points Wednesday, marking its largest-ever daily loss of 12.06 percent. Yonhap

The benchmark KOSPI recorded its largest-ever daily loss of 12.06 percent Wednesday, surpassing its previous record of 12.02 percent, which occurred after the Sept. 11 terrorist attacks on the U.S. in 2001.

The main index fell for a second consecutive day to close at 5,093.54 points, with losses accelerating amid a widening conflict in the Middle East involving the United States, Israel and Iran, building on Tuesday’s 7.24 percent decline.

The secondary bourse Kosdaq also dropped 14 percent Wednesday, compared to a 4.62 percent decline the previous day, closing at 978.44 points.

The decline was sharp enough to trigger a sidecar trading curb and next-level circuit breaker on both the KOSPI and Kosdaq during intraday trading.

The sidecar was activated at 9:06 a.m. on the KOSPI and 10:31 a.m. on the Kosdaq, as the KOSPI 200 and Kosdaq 150 — baskets of the top 200 and 150 stocks, respectively — dropped past the 5 percent threshold from the previous day’s close.

The curb temporarily halted sell orders for five minutes before trading resumed.

A circuit breaker was triggered at 11:16 a.m. on the Kosdaq and 11:19 a.m. on the KOSPI, after each index fell past the 8 percent threshold from the previous day’s close.

This suspended all trading — both buying and selling — for the next 20 minutes.

Sell-side sidecars were triggered at the same time on both the KOSPI and Kosdaq for the first time since Nov. 5, 2025, while circuit breakers were also activated concurrently for the first time since August 2024.

On the KOSPI, foreign and retail investors were net buyers of more than 231 billion won ($157.1 million) and 79.2 billion won in stocks, respectively, while institutional investors offloaded 558.7 billion won.

On the Kosdaq, foreign and institutional investors led net purchasing, acquiring 1.11 trillion won and 25.6 billion won, in contrast to retail investors, who sold a net 1.2 trillion won.

All of the top 100 stocks on the KOSPI posted losses, including Samsung Electronics, which fell 11.74 percent to 172,200 won; SK hynix, which dropped 9.58 percent to 849,000 won; and Hyundai Motor, which slid 15.8 percent to 501,000 won.

The situation was similar on the Kosdaq, where the top three companies — EcoPro, Alteogen and EcoPro BM — lost 18.41 percent, 13.32 percent and 16.99 percent, respectively.

The consecutive declines turned each bourse from the world’s top-growing index into a rapidly losing one. Before Tuesday, the KOSPI had posted the world’s fastest gain at 48.1 percent, followed by the Kosdaq at 28.88 percent.

Analysts said the rapid ascent is contributing to more negative sentiment toward the Korean stock market compared with its Asian peers, which experienced smaller declines amid heightened tensions in the Middle East.

They said the domestic stock market is undergoing a correction phase, which could last longer than expected.

“Iran’s last‑ditch resistance, despite its military capabilities appearing nearly depleted, could last longer than expected and add to the fundamental risk of an energy shock,” Huh Jae‑hwan, a researcher at Eugene Investment & Securities, said.

Lee Kyung-min, a researcher at Daishin Securities, said, “A short-term correction is inevitable, as the domestic market has been rallying faster than other global indexes, and may need further adjustment to align with the global stock market downturn.”