The KOSPI on Feb. 26 ended at 6,308.17, up 224.31 points, or 3.69 percent, from the previous session, quickly breaking above 6,300.

A day after it closed above 6,000 for the first time on a closing basis, the index opened higher at 6,121.03 and extended a record rally, setting an intraday high of 6,313.27.

Institutions and retail investors bought a net 1.2436 trillion won and 659.9 billion won, respectively, lifting the index. Foreigners posted net selling of 2.1097 trillion won, offloading shares.

The index's rise was led by large-cap stocks with heavy market capitalisation, including semiconductors and autos.

Market bellwether Samsung Electronics rose 7.25 percent from the previous day to 218,250 won. SK Hynix also surged 7.76 percent to end at 1,097,000 won, strongly underpinning the index's gain.

Hyundai Motor, the third-largest by market value, ended up 6.29 percent at 608,000 won, while No. 8 Kia rose 5.18 percent to 206,250 won. Nine of the top 10 stocks by market value rose, with the exception of HD Hyundai Heavy Industries.

The Kosdaq also closed up 22.90 points, or 1.97 percent, at 1,188.15.

It rose as high as 1,190.85 during the session, the highest level in 25 years and 6 months since Aug. 17, 2000, when it hit 1,196.50.