The KOSPI fell more than 3% on the 3rd, sliding to the 5,600 level. The 'chip duo' of Samsung Electronics and SK hynix both dropped sharply, and the KOSDAQ index also posted a drop in the 4% range.

The KOSPI closed at 5,648.79, down 210.29 points (3.59%) from the previous session. The index, which had risen more than 2% the day before despite the Intel shock, gave back all of that gain in a single day.

Renewed concerns over the profitability of artificial intelligence (AI) investment led large chip stocks to drag the market lower.

Earlier, on the 2nd (local time), the New York stock market rose right after the open as international oil prices fell sharply on hopes for peace talks between the United States and Iran, but turned lower as selling in tech stocks continued to pour in. Oracle's shares fell 8.76% after it said it would issue $10 billion each of stocks and bonds, $20 billion in total, to raise funds for AI infrastructure investment.

"Even though international oil prices and U.S. long-term interest rates fell on hopes for U.S.-Iran talks, tech stocks were weak," said Yang Hyeon-gyeong, a researcher at iM Securities. "The market appears to be focusing on recouping AI investment costs and funding burdens rather than falling rates."

In terms of supply and demand, by the close of the regular session on the Korea Exchange's main market, foreigners had dumped 1.5298 trillion won and institutions 514.7 billion won. Individuals bought 1.6643 trillion won, absorbing the flood of shares.

By stock, Samsung Electronics closed at 219,500 won, down 9,500 won (4.15%) from the previous session, and SK hynix at 1,398,000 won, down 74,000 won (5.03%). Many other top market-cap stocks also failed to avoid declines, including Samsung Electro-Mechanics (-7.38%), SK Square (-5.37%), LG Energy Solution (-5.06%), Samsung Life (-3.86%), Hyundai Motor (-3.31%), Samsung C&T (-2.21%) and KB Financial (-1.30%).

The KOSDAQ index ended trading at 704.39, down 29.97 points (4.08%). In this market too, foreigners (76.3 billion won) and institutions (234.5 billion won) were net sellers, while individuals made net purchases of 319.9 billion won. Many top stocks turned weak, including EO Technics (-8.56%), Jusung Engineering (-7.68%), Wonik IPS (-7.14%), Simmtech (-6.73%), Leeno Industrial (-6.14%), EcoPro BM (-4.89%), EcoPro (-4.88%), Rainbow Robotics (-4.00%) and HLB (-2.40%).