The KOSPI on Monday swung sharply in intraday trade before turning higher late and setting a fresh all-time closing high. Samsung Electronics rose more than 3 percent, cementing its market capitalisation in the 2,000 trillion won range and entering the top 10 in the global ranking of listed companies by market value.

The KOSPI ended up 13.11 points, or 0.15 percent, at 8,801.49. The index opened at 8,883.19 and climbed to 8,933.62, attempting to break above 9,000. It then slid to the 8,500 range and turned lower, but rebounded late to set a new record high on a closing basis.

The KOSPI showed a roller-coaster pattern throughout the session, swinging sharply up and down after the open. Profit-taking after the previous day's surge deepened losses intraday, but late buying in Samsung Electronics and some other top market-cap stocks lifted the index.

By investor type, individuals and institutions were net buyers of 6.3472 trillion won and 241.5 billion won, respectively. Foreigners were net sellers of 6.5939 trillion won. Despite heavy foreign selling, strong buying by individuals supported the lower end of the index.

Top market-cap stocks were mixed. Samsung Electronics ended at 360,500 won, up 11,500 won, or 3.30 percent, from the previous session. SK Square rose 7.17 percent to 1,346,000 won, Samsung Life climbed 17.07 percent to 480,000 won, and Samsung C&T added 6.70 percent to 485,500 won.

In contrast, SK Hynix fell 0.13 percent to 2,360,000 won. Hyundai Motor dropped 2.80 percent to 729,000 won, Samsung Electro-Mechanics slid 9.58 percent to 1,813,000 won, LG Energy Solution fell 2.75 percent to 442,500 won, and HD Hyundai Heavy Industries lost 1.61 percent to 673,000 won.

Samsung Electronics was at the centre of the market on the day. After breaking above 2,000 trillion won in market capitalisation the previous session, it extended gains on Monday and kept its valuation in the 2,000 trillion won range.

Samsung Electronics had a market value of about $1.56 trillion as of June 2026, ranking in the global top 10, according to CompaniesMarketCap, a website that tracks corporate market capitalisation. After surpassing bitcoin's market value the previous day, it has grown to a valuation comparable to major global technology stocks.

Still, differentiation was clear even among large caps, aside from Samsung Electronics and some financial and holding-company type stocks. SK Hynix ended slightly lower, while Samsung Electro-Mechanics, LG Energy Solution and HD Hyundai Heavy Industries fell, limiting the KOSPI's gains.

The KOSDAQ ended down 24.00 points, or 2.29 percent, at 1,026.03. Unlike the KOSPI's late rebound, the KOSDAQ extended weakness for a second straight day. As money concentrated in large semiconductor stocks and some top market-cap names, sentiment toward small and mid-sized growth stocks weakened relatively.

In Seoul's foreign exchange market, the won was 1,519.00 per dollar, down 4.50 won from the previous session.