The KOSPI fell on Wednesday for the first time in 3 sessions, slipping to the 8,180 level. It rose as high as the 8,250 level early in the session, but slipped below 8,000 intraday as profit-taking selling emerged led by Samsung Electronics.

The KOSPI closed down 43.41 points, or 0.53 percent, at 8,185.29. The index opened down 62.97 points, or 0.76 percent, at 8,165.73, then climbed to the 8,200 level before turning weaker again.

After setting record highs for 2 straight sessions through Tuesday, the KOSPI showed signs of a breather on the day. The move was seen as driven by growing 부담 after a sharp rise led by heavyweight semiconductor stocks, along with profit-taking in some large caps.

By investor type, retail investors were net buyers of 3.64 trillion won. Foreigners and institutions were net sellers of 2.9 trillion won and 889.5 billion won, respectively, weighing on the index. Large-scale buying by retail investors was not enough to offset selling by foreigners and institutions.

Top stocks by market capitalisation were mixed. Samsung Electronics fell 2.44 percent to 299,500 won, while SK Square fell 3.06 percent, Hyundai Motor fell 0.59 percent, HD Hyundai Heavy Industries fell 5.38 percent and Doosan Enerbility fell 2.40 percent.

SK Hynix rose 2.05 percent to 2,289,000 won. Samsung Electro-Mechanics surged 13.44 percent to 1,849,000 won, and LG Energy Solution rose 15.25 percent to 442,000 won. Samsung Life Insurance gained 0.85 percent.

The market weakness was seen as driven by a combination of profit-taking in semiconductor shares and concerns about market concentration. Samsung Electronics turned lower, weighing on the index, and caution grew over the semiconductor-led rally that ran through Tuesday. SK Hynix held gains, showing stock-specific divergence even within semiconductor shares.

The KOSDAQ closed down 28.73 points, or 2.54 percent, at 1,104.40. Investor sentiment toward small and mid-cap growth stocks was relatively weak as trading remained focused on KOSPI large caps.

In the Seoul foreign exchange market, the won stood at 1,501.90 per dollar, up 0.10 won from the previous session.

Kiwoom Securities researcher Ji-young Han (한지영) cited a renewed increase in U.S.-Iran geopolitical noise, a surge in oil prices and rising domestic and overseas market interest rates, weakness in U.S. semiconductor shares, and concerns about concentration in domestic semiconductor shares as reasons behind the market pullback.

Han said, "Given that the sharp drop occurred in an environment where no unusual factors emerged in the existing drivers of gains such as earnings and valuations, it is right to see it as part of a short-term breather process that does not break the existing upward trend."