[Edaily Reporter Kim Hyung-il ] The KOSPI rebounded sharply by more than 5% just one day after plunging more than 5% the previous day. The KOSPI, which had triggered a “sell-side car” the previous day, saw the “buy-side car” activated today, completely reversing the market sentiment in a single day. Investor sentiment recovered as major semiconductor stocks—including SamsungElectronics(005930)and SK hynix—soared following SK hynix(000660)’s announcement of a 40 trillion won buyback and cancellation of its own shares, coupled with a stabilization in the rise of U.S. long-term interest rates.

According to MP Doctor on the 20th, the KOSPI closed at 6,852.58, up 381.41 points (5.89%) from the previous trading day. The KOSPI opened 3.23% higher at 6,680.34 and, in the afternoon, briefly rose as much as 6% to reach the 6,900 level, though it later gave up some of those gains. There were 521 gainers, 338 losers, and 46 stocks that closed unchanged.

A strong rebound continued from the start of the session, triggering a buy-side sidecar. At 9:57 a.m., the KOSPI 200 futures price rose 5.1% from the reference price of 1,016.25 to 1,068.15 and remained at that level for one minute, triggering the buy-side sidecar. As a result, the execution of buy orders via program trading was suspended for five minutes. This marks the first buy-side sidecar in five trading days since the 12th. Notably, the buy-side sidecar was triggered just one day after a sell-side sidecar was activated due to the KOSPI’s sharp decline the previous day. This is the 49th sidecar triggered so far this year, with 25 sell-side sidecars and 24 buy-side sidecars.

In terms of supply and demand, foreign investors drove the index higher with net purchases totaling 1.7079 trillion won. Retail investors recorded net sales of 2.2714 trillion won, while institutional investors sold a net 490.4 billion won. Foreign investors’ large-scale net buying supported the KOSPI’s rebound following the previous day’s sharp decline.

The KOSPI saw a notable rally led by large-cap stocks. Large-caps rose 6.36%, while mid-caps and small-caps rose only 0.67% and 0.94%, respectively. By sector, the electrical and electronics sector surged 9.19%, and the manufacturing sector also rose 7.1%. The securities (4.46%) and retail (4.16%) sectors also showed strength.

SamsungElectronics closed at 271,000 won, up 9.49%. SK hynix rose 12.73% to 1,691,000 won, approaching the 1.7 million won mark. SamsungElectronics(1P)(005935)surged 10.07%, and SKSQUARE(402340)soared 11.85%. SAMSUNG C&T CORPORATION(028260)rose 7.78%, and SAMSUNG BIOLOGICS(207940)rose 1.94%. In contrast, HANWHA AEROSPACE fell 0.85%.

SK hynix surged after announcing, following the market close the previous day, a plan to repurchase and fully cancel 40 trillion won worth of its own shares. This amounts to approximately 3.3% of the total number of issued shares. The company also expanded its shareholder return policy based on cumulative free cash flow (FCF) from “up to 50%” to “50% or more.” Expectations for shareholder returns also spread, particularly among major semiconductor stocks, following reports that SamsungElectronics is planning a shareholder return program in the 100 trillion won range.

U.S. stock markets also rebounded, breaking a three-day losing streak. The rise in long-term interest rates subsided after the U.S. Treasury announced it would at least double the scale of its buyback of long-term Treasury bonds with maturities of 10 to 30 years, and healthcare stocks performed strongly on news of successful Phase 3 clinical trials for mRNA-based cancer treatments by Moderna and Merck.

Lim Jeong-eun, an analyst at KB Securities, commented, “With the interest rate burden—which was the key factor behind yesterday’s correction—partially eased, combined with the news of SK hynix’s shareholder returns, the foundation for a rebound was strengthened.” She added, “Both major indices opened higher, recovering from the previous day’s losses, and the KOSPI even triggered a buy-side circuit breaker.” She added, “As positive momentum is spreading across the sector, we believe there is a strong likelihood that the rebound trend will continue.”

The KOSDAQ also reversed the previous day’s losses, closing up 1.99% at 840.89. The KOSDAQ opened 2.37% higher at 843.99, pared its gains during the morning session, but rebounded again in the afternoon. There were 1,064 gainers, 576 decliners, and 86 stocks unchanged, with 5 hitting the daily upper limit and 1 hitting the daily lower limit.

Among individual KOSDAQ stocks, the market leader, Alteogen Inc.(196170), surged 11.86%, while ECOPRO BM CO., LTD.(247540)(3.92%), JUSUNG ENGINEERING Co.,Ltd.(036930)(3.32%), WONIK IPS Co.,Ltd.(240810)(4.21%), and ABL Bio Inc.(298380)(3.51%) also rose. In contrast, HLB INC.(028300)fell 5.23%. By sector, general services posted the largest gain, rising 5.38%, while telecommunications (3.59%) also showed strength. In terms of KOSDAQ supply and demand, retail investors were net buyers of 900 million won, and institutional investors were net buyers of 112.4 billion won, while foreign investors were net sellers of 127.8 billion won.