[Edaily Reporter Kim Hyung-il ] The KOSPI plunged more than 2% early in the session but then turned higher, successfully staging a “V-shaped rebound.” The KOSDAQ also surged more than 5%, triggering the 17th “buy-side sidecar” (temporary suspension of buy orders in program trading) this year, as investor sentiment rapidly recovered.

According to MP Doctor on the 4th, the KOSPI closed at 6,358.95, up 101.50 points (1.62%) from the previous trading day. Although the index fell as low as 6,080.25 early in the session—a 2.83% decline—it quickly recovered its losses and turned positive, showing significant volatility as it briefly rose to 6,389.40 during the session.

The KOSDAQ closed at 780.72, up 43.37 points (5.88%) from the previous trading day. After opening at 748.19 early in the session, it extended its gains, continuing its upward trend and reaching as high as 780.85 during the session.

On this day, the 17th buy-side sidecar of the year was triggered in the KOSDAQ market. The Korea Exchange announced at 10:47 a.m. that the KOSDAQ 150 futures had risen 6.09% and the KOSDAQ 150 Index had risen 6.5% compared to the previous day, meeting the trigger criteria. So far this year, a total of 30 “side car” mechanisms—including 17 buy-side and 13 sell-side triggers—have been activated in the KOSDAQ market, marking the highest number since the system was introduced in 2001.

Lim Jeong-eun, an analyst at KB Securities, noted, “U.S. stock markets closed higher as oil prices and interest rate pressures eased following President Trump’s decision to call off the planned airstrike on Iran.” She added, “Although gains in large-cap semiconductor and automotive stocks were limited in the domestic market, rotational buying spread across sectors including defense, nuclear power, and cosmetics, while strength in biotech and robotics stocks drove the KOSDAQ rally.” She added, “It will be worth watching whether this week’s AMD earnings announcement leads to a turnaround in the sentiment surrounding semiconductor stocks, which have recently shown relatively weak upward momentum.”

By investor type, retail investors on the KOSPI bought 818.4 billion won worth of stocks, absorbing selling pressure from institutions and foreign investors. Institutions and foreign investors sold 539.2 billion won and 370.6 billion won worth of stocks, respectively. On the KOSDAQ, institutions bought 543.4 billion won worth of stocks, driving the index higher, while retail investors and foreign investors sold 258.6 billion won and 277.2 billion won worth of stocks, respectively.

Among the top KOSPI stocks by market capitalization, SamsungElectronics(005930)(0.63%), SK hynix(000660)(1.40%), LG Energy Solution(373220)(3.80%), SAMSUNG BIOLOGICS(207940)(3.30%), and SKSQUARE(402340)(3.71%) closed higher. On the other hand, SamsungElectronics(1P)(005935)(-0.90%), HyundaiMotor(005380)(-0.38%), KB Financial Group(105560)(-0.35%), and Samsung Life Insurance(032830)(-3.65%) were among the decliners. While leading semiconductor and secondary battery stocks showed strength, some financial and automotive stocks were weak, continuing the trend of stock-specific divergence.

By market capitalization, large-cap stocks (1.44%), mid-cap stocks (4.03%), and small-cap stocks (2.70%) all rose. By sector, construction (8.87%) posted the highest gain. GS Engineering & Construction Corp(006360)(18.56%), DaewooEngineering&Construction(047040)(14.29%), and HyundaiEngineering&Construction(000720)(5.75%) all posted strong gains, a move interpreted as reflecting optimism regarding the 2026 tax reform plan announced the previous day. Following these, the telecommunications (5.56%), metals (5.45%), machinery and equipment (4.95%), and chemicals (3.87%) sectors also rose. In contrast, the retail (-0.42%) sector showed weakness.

On the KOSDAQ, leading stocks such as Alteogen Inc.(196170)(9.29%), along with LigaChem Biosciences(141080)(15.51%), ABL Bio Inc.(298380)(13.52%), HLB INC.(028300)(10.84%), ECOPRO CO., LTD(086520)(6.46%), ECOPRO BM CO., LTD.(247540)(5.79%), and JUSUNG ENGINEERING Co.,Ltd.(036930)(6.42%) all closed higher. In contrast, WONIK IPS Co.,Ltd.(240810)(-2.99%) fell.

Rising stocks also dominated the market overall. On the KOSPI market, 788 stocks rose—including one that hit the daily upper price limit—while only 96 stocks fell. Thirty-one stocks remained unchanged. On the KOSDAQ market, 1,505 stocks rose—including 11 that hit the daily upper price limit—while 175 stocks fell. Forty-seven stocks remained unchanged.