The KOSPI rose 231.68 points or 3.56 percent to close at 6,747.95 as a buy-side sidecar was activated on the main bourse after the index's gains accelerated.
It opened 0.58 percent higher at 6,553.88 and fell to an intraday low of 6,429.03 during early volatile trading before climbing as high as 6,836.86.
Buying strengthened in the afternoon as investors returned to semiconductor shares following the previous session's sharp selloff.
A buy-side sidecar was activated at around 12:41 p.m., temporarily suspending program buy orders for five minutes. It was the 39th sidecar activation of the year and the 19th on the buy side.
Institutional investors purchased 1.3744 trillion won ($931.8 million) worth of KOSPI shares, while foreign investors bought 295.1 billion won. Retail investors sold 1.6421 trillion won.
Samsung Electronics jumped 6.2 percent to 259,000 won, while SK hynix gained 4.1 percent to 1,836,000 won. Samsung C&T surged 8.2 percent to 343,500 won and SK Square climbed 6.46 percent. Samsung Biologics rose 3.72 percent, Samsung Electro-Mechanics gained 2.75 percent and Naver advanced 3.8 percent to 193,000 won.
Hanmi Semiconductor added 0.9 percent to 224,000 won. In contrast, Hanwha Ocean fell 1.6 percent to 81,900 won, while LG Energy Solution, Celltrion and Hana Financial Group slipped 0.16 percent, 0.58 percent and 0.60 percent, respectively.
Semiconductor and semiconductor equipment shares gained 5.2 percent, led by a 29.9 percent surge in Zinitix and a 23.1 percent rise in Ajin Extek. Diversified companies advanced 4.8 percent, while life insurers gained 4.4 percent.
Robot-related shares were also among the strongest performers. Everybot and Cosmo Robotics both surged 30 percent, while Elensys jumped 30 percent as physical artificial intelligence and humanoid-related shares rallied.
A total of 485 KOSPI-listed stocks advanced, while 382 declined and 47 were unchanged.
The tech-heavy KOSDAQ rose 3.70 points or 0.49 percent to close at 753.34. The index opened 0.06 percent higher at 750.07. It fell to an intraday low of 730.81 before recovering to reach a session high of 758.36.
Retail investors purchased 144.9 billion won worth of KOSDAQ shares. Foreign investors sold 134.3 billion won, while institutions unloaded 14.4 billion won.
Zinitix surged 29.9 percent, Ajin Extek gained 23.1 percent and Nature Cell climbed 9 percent to 24,750 won.
Samchundang Pharmaceutical plunged 29.8 percent to 167,800 won, while Kolon TissueGene tumbled 29.9 percent to 42,900 won.
Among the most actively traded shares, SI Resources surged 29.6 percent and Cho-A Pharmaceutical jumped 29.8 percent. JW Shinyak rose 6.2 percent to 2,145 won, while Mirae Life Resources fell 6.6 percent to 2,460 won.
A total of 983 KOSDAQ-listed stocks rose, while 657 declined and 96 were unchanged.
The Korean won strengthened against the U.S. dollar, trading at 1,475.0 won per dollar.
Japan's Nikkei 225 jumped 3.3 percent to 66,232.2. China's Shanghai Composite Index rose 1.7 percent to 3,861.3, while Hong Kong's Hang Seng Index edged up 0.1 percent to 25,165.6.
Brent crude rose 0.2 percent to $89.4 a barrel, while West Texas Intermediate gained 0.6 percent to $83.0 a barrel.
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