[Edaily Reporter Kim Kyung-eun ] Just one day after rebounding, the KOSPI plunged by more than 6%, falling back below the 7,000 mark. The KOSDAQ also dropped by more than 4%, falling below the 800 mark. Volatile trading continued throughout the morning, with sell-side “side-car” mechanisms (temporary suspension of program sell orders) triggered successively on both the KOSPI and KOSDAQ markets.

According to MP Doctor on the 16th, the KOSPI closed at 6,820.60, down 463.81 points (6.37%) from the previous trading day.

The index opened at 6,960.50, down 323.91 points (4.45%) from the previous close, and the decline accelerated throughout the day. At one point during the session, it plummeted 7.6% to 6,730.87.

In the market, foreign investors and institutions led a joint selling spree. Foreign investors recorded net sales of 1.3761 trillion won, while institutions recorded net sales of 2.3666 trillion won. Although retail investors acted as the sole buyers with net purchases of 3.6581 trillion won, they were unable to defend the 7,000-point level (KOSPI 7,000 points).

By sector, telecommunications, food & beverages/tobacco, paper & wood, and textiles & apparel were strong. In contrast, electrical & electronics, manufacturing, machinery & equipment, and construction were weak.

SamsungElectronics(005930)and SK hynix(000660), the blue-chip stocks of the domestic market, both plummeted. SamsungElectronics closed at 255,000 won, down 24,500 won (8.77%) from the previous session, while SK hynix closed at 1,836,000 won, down 246,000 won (11.82%).

This is interpreted as the domestic stock market being affected by the weak performance of semiconductor stocks on the New York Stock Exchange overnight, driven by concerns over artificial intelligence (AI) infrastructure investment. On the 15th (local time), while the three major U.S. stock indices all rose, semiconductor stocks saw profit-taking. SK hynix’s American Depositary Receipts (ADRs) fell 9.00% that day after surging 27.29% the previous day.

Kim Yu-mi, an analyst at KIWOOM Securities, said, “Concerns over delays in data center construction, among other factors, contributed to the correction in semiconductor stocks,” but added, “Given the strong performance of major platform companies, expectations for AI investment demand remain valid.”

The Bank of Korea’s Monetary Policy Committee raised the benchmark interest rate by 0.25 percentage points from 2.50% to 2.75% during its monetary policy meeting this morning. However, since this move was already on a predictable path, its impact on the market is expected to be limited.

Kang Jin-hyuk, an analyst at Shinhan Investment Securities, noted, “Stocks related to the AI value chain plummeted amid selling pressure following the previous day’s sharp rally and lingering doubts about the semiconductor sector,” adding, “Although the Monetary Policy Committee raised the benchmark interest rate for the first time in three years and six months, the impact on the stock market was limited because this move had already been factored into the market.”

The KOSDAQ index closed at 791.84, down 37.59 points (4.53%) from the previous session. The index opened at 813.32, down 16.11 points (1.94%) from the previous trading day, but continued its downward trend, falling below the 800 mark.

In the KOSDAQ market, foreign and institutional investors sold 303.6 billion won and 156.3 billion won worth of stocks, respectively. Retail investors were net buyers, purchasing 446.7 billion won worth of stocks.

The two stocks with the largest market capitalizations also fell in tandem. Alteogen Inc.(196170)closed at 276,500 won, down 12,000 won (4.16%) from the previous session, while ECOPRO BM CO., LTD.(247540)closed at 112,500 won, down 8,400 won (6.95%).

Amid the sharp market decline that day, sell-side circuit breakers were triggered consecutively on both the KOSPI and KOSDAQ markets.

According to the Korea Exchange, at approximately 9:10:26 a.m., the effectiveness of program sell orders on the KOSPI market was suspended for five minutes due to fluctuations in the KOSPI 200 futures index. The KOSPI sell-side sidecar is triggered when the KOSPI 200 futures index falls by 5% or more and the decline persists for one minute.

Subsequently, at approximately 10:20:00 a.m., a sell-side circuit breaker was triggered in the KOSDAQ market. The KOSDAQ sell-side circuit breaker is triggered when the KOSDAQ 150 Index falls by 3% or more, or the KOSDAQ 150 futures contract falls by 6% or more, and the decline persists for one minute.

This marks the 19th time this year that the KOSPI sell-side car has been triggered and the 9th time for the KOSDAQ. Both the KOSPI and KOSDAQ sell-side cars were triggered for the second time in two trading days since the 14th.