South Korea: stock market sessions and KOSPI

The index had fallen as low as 5,599.42. The decline in futures triggered a sell-side sidecar, temporarily suspending program sell orders without closing the entire market.

Samsung Electronics ended down 3.02% and SK hynix down 7.08%, according to Aju Press. That outlet and Yonhap link the movement to concerns about returns on artificial intelligence investments following losses in U.S. technology shares.

The 3.48% loss is the closing change; the fall of more than 5% describes a point during the session.

The mechanism, known as a buying sidecar, applies to programme orders when KOSPI 200 futures pass the specified upward threshold. It does not close the entire stock exchange.

In its 11:47 a.m. update, YTN reported that the index had briefly passed 6,000 before trading in the mid-5,900s. These are intraday levels, rather than a closing value.

YTN linked momentum in major semiconductor shares to SK hynix's results and renewed interest in AI. That explanation remains the broadcaster's analysis.

The index opened at 5,499.05 and briefly erased its losses before finishing lower. Investing.com’s historical data and Yonhap’s reporting agree on the closing level.

Yonhap describes caution ahead of major chipmakers’ earnings and the US Federal Reserve’s decision. That account of the backdrop does not establish a single cause for every price movement.