[Edaily Reporter Hyera Lee ] Both markets closed higher. The buy-side circuit breaker was even triggered at one point during the session on the KOSPI.

According to MP Doctor on the 21st, the KOSPI closed at 6,747.95, up 231.68 points (3.56%) from the previous trading day.
The index opened at 6,553.88, up 0.58%, early in the session. Shortly after the regular session began, the KOSPI turned negative and hit a low of around 6,440. Thirty-five minutes after the opening, it successfully turned positive again and continued to extend its gains throughout the day, marking a return to positive territory for the first time in two days.
Volatility continues to persist. On the stock market, following the previous day’s sell-side circuit breaker, a buy-side circuit breaker was triggered at 12:41 p.m. today. The buy-side circuit breaker has been triggered 19 times so far this year. A buy-side car is triggered when the price of the KOSPI 200 futures contract with the highest trading volume on the previous trading day rises by 5% or more and remains at that level for one minute. A sell-side car has been triggered 20 times this year.
On this day, buying by both foreign investors and institutions drove the market higher. Foreign investors bought for the second consecutive day, recording a net buying position of approximately 614.4 billion won. Institutions switched to net buying for the first time in two days, purchasing over 1.6 trillion won worth of shares. In contrast, retail investors sold off 2.1647 trillion won worth of shares. Program trading showed a net buying position of 1.1503 trillion won, combining both arbitrage and non-arbitrage trades.
Stocks with the highest market capitalization also generally closed in positive territory.
Among the top 15 stocks by market capitalization, only two— HyundaiMotor(005380)(unchanged) and LG Energy Solution(373220) —did not rise.
SamsungElectronics(005930) SK hynix(000660)and rose 6.15% and 4.08%, respectively. In addition, , , , , , and all posted gains. SKSQUARE(402340) SamsungElectroMechanics(009150) SAMSUNG BIOLOGICS(207940) Samsung Life Insurance(032830) KB Financial Group(105560) KIA CORPORATION(000270)
SAMSUNG BIOLOGICS announced the previous day that it had decided to acquire Poly Peptide, a Swiss contract development and manufacturing organization (CDMO) specializing in peptides, for 2.7 trillion won. The stock closed up around 4% as buying interest surged on expectations that SAMSUNG BIOLOGICS would make a full-scale entry into the global CDMO market for obesity treatments. At the same time, SAMSUNG C&T CORPORATION(028260)closed at 343,500 won, up 8.19%. SAMSUNG C&T CORPORATION currently holds a 43.06% stake in SAMSUNG BIOLOGICS.
By stock, at the same time, the market tallied 486 gainers (including one hitting the daily upper limit), 384 losers, and 47 stocks trading flat (including two hitting the daily lower limit).
The KOSDAQ index rose 3.70 points (0.49%) from the previous trading day to close at 753.34 points.
The KOSDAQ, which opened slightly higher, slipped into negative territory shortly after the opening bell, mirroring the KOSPI. It stabilized in positive territory during the afternoon session and closed higher for the first time in two days.
In the KOSDAQ market, retail investors were the sole buyers, purchasing 139.1 billion won worth of stocks. In contrast, foreign investors and institutions sold 140.9 billion won and 6.2 billion won worth of stocks, respectively.
Most of the top-market-cap stocks on the KOSDAQ also closed higher. However, performance varied significantly from stock to stock.
Among the top 15 stocks by market capitalization, Kolon TissueGene, Inc.(950160)and SAM CHUN DANG PHARM CO. LTD(000250)plummeted.
In particular, Kolon TissueGene, Inc.’s preliminary results from its U.S. Phase 3 clinical trial worsened investor sentiment toward biotech stocks. Kolon TissueGene, Inc. announced the previous day that “TG-C,” its cell-gene therapy for knee osteoarthritis, had failed to demonstrate efficacy in the preliminary results of its U.S. Phase 3 clinical trial.
Kolon TissueGene, Inc. closed at 42,900 won, down 29.90%.
SAM CHUN DANG PHARM CO. LTD, which had closed at the daily price limit the previous day, also fell by around 29%. SAM CHUN DANG PHARM CO. LTD had announced the previous day that it had received a Pre-ANDA response from the U.S. Food and Drug Administration (FDA), a consultative process preceding the submission of an Abbreviated New Drug Application (ANDA) for an oral semaglutide generic. This response is a document sent by the FDA after officially reviewing the company’s development strategy and does not imply approval. Pre-ANDA is a system through which the FDA consults in advance on development strategies, reference drugs, and bioequivalence test plans prior to a generic drug application.
Rainbow Robotics(277810)rose by over 9%, posting the largest gain among the top 10 stocks. Rainbow Robotics closed at 411,500 won, up 9.73% from the previous trading day. This is interpreted as buying interest flowing into Rainbow Robotics, SamsungElectronics’ robotics subsidiary, following the company’s announcement today of the establishment of a new organizational unit, the “RX (Robotics Experience) Business Promotion Office,” to focus on its robotics business as a future growth engine. Rainbow Robotics even extended its gains to the 18% range at one point during the trading session.
On the KOSDAQ market, 1,002 stocks rose—including 19 that hit their daily upper price limit—while 662 fell—including 5 that hit their daily lower price limit—and 96 remained unchanged.
The securities industry is closely watching the U.S. Big Tech earnings season, which is set to kick off in earnest this week. In the U.S., major Big Tech companies are scheduled to release their second-quarter earnings starting with Alphabet on the 23rd (local time). The market is expected to gauge the impact on the AI investment trend and the domestic semiconductor sector based on these companies’ earnings and estimates.
There are also views that during the domestic second-quarter earnings season, it will be important to confirm whether the trend of profit improvement is spreading beyond the semiconductor sector to other industries such as finance and retail.
Choi Jae-won, an analyst at KIWOOM Securities, emphasized, “Sectors such as IT hardware, retail and distribution, and securities are showing profit growth, with high year-over-year operating profit growth rates expected,” adding, “During this earnings season, the direction of recent changes in estimates is more important than the earnings growth rate itself.”