The KOSPI, which had plunged for two straight sessions, rebounded in a day. It slid below the 6,500 level early in the session, then recovered the 6,800 level intraday in a roller-coaster market. Bargain hunting flowed in to pare losses, but extreme volatility persisted, with a sidecar triggered in the main board for the fourth straight day.
On the 21st, the KOSPI finished at 6,747.95, up 231.68 points (3.56%) from the previous session. Opening at 6,553.88, the KOSPI turned lower right after the open and fell to as low as 6,429.03 intraday, but reversed higher as foreign and institutional buying came in. It then expanded gains and at one point topped the 6,800 level intraday.
During the rebound, a buy sidecar was triggered, temporarily suspending the effect of program buy quotes. According to the Korea Exchange (KRX), a buy sidecar was triggered at about 12:41 p.m. that day, marking the fourth straight session with a sidecar after a buy sidecar on the 15th and sell sidecars on the 16th and 20th. So far this year, there have been 39 sidecar triggers on the main board.
Flows were led by foreigners and institutions. According to the Korea Exchange (KRX) and NEXTRADE (NXT), in the main board foreigners were net buyers of 640 billion won and institutions 1.54 trillion won. Among institutions, the national pension funds also maintained a buying bias. Individuals, meanwhile, were net sellers of more than 2 trillion won, taking profits.
Among large-cap stocks, semiconductor shares led the rebound. Samsung Electronics(005930) and SK hynix rose 6% and 4%, respectively, while holding companies SK Square and Samsung C&T climbed 6% and 8%, respectively. Bargain hunting also flowed into power equipment names such as LS Electric and HD Hyundai Electric, which showed strength.
The securities industry interpreted the day's rebound as a technical bounce rather than a trend reversal.
Lee Kyung-min of Daishin Securities said, "With bargain hunting centered on the semiconductor sector, risk appetite partially recovered as Pakistan and Qatar moved to mediate between the United States and Iran," adding, "In the U.S. market the previous day, dip-buying flowed into recently plunging semiconductor stocks, and positive investment opinions from global investment banks (IBs) on the memory sector also supported sentiment."
In fact, on the 20th (local time), Morgan Stanley released a report with an optimistic outlook for the memory semiconductor sector. Joseph Moore, a Morgan Stanley analyst, said, "This memory cycle is highly unusual in that data center demand is virtually the only growth driver," presenting the recent correction in memory semiconductor stocks as a buying opportunity. Moore projected that memory shortages will continue through 2028 as investment in artificial intelligence (AI) data centers expands.
Another analysis said the sharp drop in stock prices over a short period, which significantly eased valuation pressure, also spurred bargain hunting.
Kim Dae-jun of Korea Investment & Securities Co. said, "As of the previous day, the KOSPI's 12-month forward price-earnings ratio (PER) was 5.6 times, down to a historical bottom range, so the room for further decline is limited," adding, "If support is confirmed at the 120-day moving average, a rebound trend can be expected."
The KOSDAQ also overcame early weakness to finish higher. The KOSDAQ index closed at 753.34, up 3.70 points (0.49%) from the previous session. It fell to the 730 level at one point intraday, but in the afternoon recovered all the losses and turned higher.
In the KOSDAQ market, individuals were net buyers of 139 billion won, while foreigners were net sellers of 140 billion won and institutions also showed a slight selling bias.
Among large-cap names, most finished higher, including Alteogen, EcoPro BM and EcoPro. In contrast, Sam Chun Dang Pharm(000250), which hit the upper price limit the previous day on news it had received a response letter from the U.S. Food and Drug Administration (FDA), closed at the lower price limit as caution spread that the approval process had not been finalized.