KOSPI Surges 5% on US-Iran Ceasefire News... Buy-Side Circuit Breaker Triggered

KOSPI Buy-Side Circuit Breaker Triggered Amid Sharp Rally in Early Trading
KOSDAQ Index Also Up Over 3%... Samchundang Pharm Weakens
"Market Reacts to Eased Concerns, But Full Resolution Still Pending"

With the United States and Iran effectively agreeing to extend the ceasefire by two weeks, both the KOSPI and KOSDAQ indices showed an upward trend in the early hours of trading. The Korea Exchange experienced such a sharp surge that a buy-sidecar program was triggered immediately after the market opened.

On the 8th, when news broke that the United States and Iran had agreed to a two-week ceasefire, the KOSPI index surged over 6% immediately after the market opened. Various indices are displayed on the status board in the dealing room of Hana Bank in Jung-gu, Seoul. 2026.04.08 Photo by Dongju Yoon

As of 9:32 a.m. on April 8, the KOSPI index was trading at 5,799.31, up 5.54% (304.53 points) from the previous trading day. Foreign investors and institutions recorded net purchases of KRW 1,202.995 billion and KRW 2,153.26 billion, respectively, while individual investors posted net sales of KRW 3,318.781 billion.

Due to the rapid market surge, at 9:06:02 a.m., a buy-sidecar was activated, temporarily suspending program buy orders in the Korea Exchange. At the time the sidecar was triggered, the KOSPI200 futures index was at 875.45, up 51.35 points (6.23%) from the previous trading day. The KOSPI buy-sidecar is activated when the KOSPI200 futures price rises by more than 5% from the base price for a minute or longer, and it suspends the effectiveness of program buy orders for five minutes.

By sector, all industries except paper and wood (-1.87%) showed strong performance. Notably, construction (11.59%), electricity and gas (8.62%), securities (7.25%), finance (6.77%), electrical and electronics (6.70%), and machinery and equipment (5.95%) posted high gains.

Among the top market cap stocks, most were also showing gains except for a few. Samsung Electronics, which reported earnings that exceeded market expectations the previous day, was trading at KRW 209,500, up 6.6% (KRW 13,000). SK hynix was trading at KRW 1,002,000, up 9.3% (KRW 86,000).

Other notable gainers, each rising by around 10% or more, included SK Square (14.8%), Doosan (14.5%), Hyosung Heavy Industries (12.4%), Hyundai Engineering & Construction (12.1%), Samsung C&T (10.5%), HD Hyundai Electric (9.8%), and Korea Electric Power Corporation (9.7%). In contrast, with expectations rising for an end to the Iran conflict, defense industry stocks such as Hanwha Aerospace (-3.8%) and Hanwha Systems (-1.4%) saw declines. Some other stocks, like LG Energy Solution (-0.9%), also showed downward movement.

As of the same time, the KOSDAQ index was trading strongly at 1,075.62, up 3.75% (38.89 points) from the previous trading day. Foreign investors made net purchases of KRW 49.921 billion, and institutions net purchased KRW 335.742 billion, while individuals recorded net sales of KRW 379.677 billion.

By sector, all industries except food, beverage, and tobacco (-0.03%) posted gains. Machinery showed the highest increase at 5.52%, followed by non-metallic minerals (4.43%), general services (4.30%), chemicals (4.24%), and electrical and electronics (4.24%).

Among top market cap stocks, most were also strong, including Woori Technology (11.5%), HPSP (7.5%), Rainbow Robotics (7.1%), Alteogen (6.7%), Caregen (6.5%), Robotis (6.0%), ABL Bio (5.7%), Ecopro (4.2%), and Ecopro BM (3.2%). However, Samchundang Pharm (-9.9%) was notably weak.

Suh Sangyoung, a researcher at Mirae Asset Securities, commented, "The market is cheering the fact that the threat of a large-scale attack has been alleviated for now," but also noted, "However, there are still concerns since Iran is not expected to relinquish its grip on the Strait of Hormuz, Israel has not responded, and attacks on Lebanon are expected to continue."

Meanwhile, in the Seoul foreign exchange market, the won-dollar exchange rate opened at 1,479.9 won, down 24.3 won from the previous trading day.

This content was produced with the assistance of AI translation services.