The KOSPI is displayed at the dealing room of Hana Bank headquarters in Jung-gu, Seoul, on the 4th, after plunging by 12% to below 5,100 due to the fallout from the potential outbreak of war between the U.S. and Iran. On this day, the KOSPI closed at 5,093.54, down 698.37 points (12.06%) from the previous trading day, and the KOSDAQ closed at 978.44, down 159.26 points (14.00%). [Yonhap News]

South Korea's stock market plummeted on the 4th due to the fallout from the potential outbreak of war between the U.S. and Iran, leading to a string of ignominious records.

On this day, the KOSPI closed at 5,093.54, down 698.37 points (12.06%) from the previous trading day.

The KOSPI's rate of decline on this day was the largest in history. The previous record was 12.02% set on September 12, 2001. At that time, the domestic stock market also faltered in tandem with the sharp decline in the U.S. stock market due to the aftermath of the '9/11 terrorist attacks'.

The magnitude of the KOSPI's decline on this day was also the largest in history. The KOSPI had fallen by 452.22 points the day before due to escalating tensions in the Middle East, marking the largest single-day drop in history, only to surpass that record within a day.

The cumulative decline over the past two days has reached 1,150.59 points.

The market capitalization of KOSPI was 4,194 trillion 946.8 billion won, a decrease of 574 trillion 486.0 billion won from the previous day (4,769 trillion 433.0 billion won).

This represents the largest single-day decrease in market capitalization in the stock market's history.

The KOSDAQ index also closed at 978.44, down 159.26 points (14.00%) from the previous trading day.

The rate of decline for the KOSDAQ on this day was also the highest. The previous record for the highest rate of decline was 11.71% recorded on March 19, 2020, during the COVID-19 pandemic.

The market capitalization of KOSDAQ on this day was 538 trillion 114.0 billion won, a decrease of 87 trillion 265.0 billion won from the previous day (625 trillion 379.0 billion won).

This also marks the largest single-day decrease in KOSDAQ market capitalization in history. The combined market capitalization of KOSPI and KOSDAQ has decreased by over 1,000 trillion won in the two days since the 3rd.

Reflecting the market's anxiety on this day, the 'KOSPI 200 Volatility Index' (VKOSPI), known as the Korean Fear Index, closed at 80.37, a surge of 27.61% from the previous trading day, recording its all-time high.

During trading hours, it briefly reached 80.85, also setting a new intraday record high.

The VKOSPI is an index that measures the expected market volatility reflected in option prices. It tends to surge when the KOSPI plunges, hence its nickname 'Fear Index'.

Trading volume also surged amidst intense supply and demand dynamics during the sharp decline.

On this day, the trading volume in the stock market reached 58 trillion 688.0 billion won, a record high. The previous record high was 54 trillion 939.0 billion won recorded on the 27th of last month.

Measures to mitigate the impact of the market crash were triggered one after another.

Around 11:16 AM on this day, the KOSDAQ index remained down more than 8% for one minute, triggering a circuit breaker in the KOSDAQ market, which temporarily halted trading for 20 minutes.

Following this, a circuit breaker was also triggered in the KOSPI market starting at 11:19:12 AM. This is the first time in one year and seven months since August 5, 2024, that circuit breakers were simultaneously activated in both markets.

On August 5, 2024, the KOSPI plunged 8.77% and the KOSDAQ index fell 11.3% in a single day as fears of a recession, triggered by weak U.S. employment data, swept through the market.

Since the system's introduction, this marks the 7th time a circuit breaker has been triggered in the stock market and the 11th time in the KOSDAQ market.

South Korea's futures market also experienced volatility on this day.

As KOSPI 200 futures prices plummeted, a "sidecar," which suspends the effect of program sell orders for five minutes, was triggered around 9:06:02 AM for the second consecutive day, following its activation the previous day.

Additionally, as KOSDAQ 150 futures and spot prices sharply declined, a sidecar, which suspends the effect of program sell orders in the KOSDAQ market, was triggered around 10:31:06 AM, marking its first activation in four months.

This is the first time in four months, since November 5 of last year, that sell-side cars for both KOSPI and KOSDAQ were activated on the same day.