On the 18th, the KOSPI plunged more than 3% intraday, also breaking below the 3,970 level. Bitcoin surrendered the $90,000 mark intraday for the first time in seven months.

As of 1:11 p.m., the KOSPI was trading at 3,966.25, down 123 points (3.01%) from the previous session. Having opened at 4,044.47, down 44.78 points (1.10%), the index extended losses, successively giving up the 4,000 and 3,970 thresholds.

The KOSDAQ was also weak. As of 1:19 p.m., the KOSDAQ index was trading at 874.37, down 28.30 points (3.14%) from the previous session, with the 900 level broken.

As expectations for a December rate cut by the U.S. Federal Reserve (Fed) weakened and concerns about an artificial intelligence (AI) bubble resurfaced, risk assets slumped, weighing on the domestic stock market.

On the KOSPI, decliners accounted for more than 90%, with broad weakness across sectors. Samsung Electronics traded at 97,700 KRW, down 2,900 KRW (2.88%) from the previous session, losing the 100,000 KRW level, and SK hynix plunged 34,500 KRW (5.69%) to 571,500 KRW, slipping below 600,000 KRW.

Most large caps were lower, dragging the index down, including Hyundai Motor (-2.21%), Hanwha Aerospace (-5.11%), and KB Financial (-3.47%).

On the main board that day, retail investors were net sellers of 802.3 billion KRW, while foreigners and institutions were net sellers of 253.4 billion KRW and 571.8 billion KRW, respectively.

Amid risk-off sentiment, other risk assets beyond the KOSPI also weakened. As of 1:21 p.m. Korea time on the 18th, Bitcoin was trading at $89,892.92 on global crypto exchange Coinbase, down 5.81% from the previous day. It was the first time in seven months, since April, that Bitcoin fell below $90,000.