Financial data is shown on a screen at the dealing room of Hana Bank in downtown Seoul on Thursday. (Yonhap)
Financial data is shown on a screen at the dealing room of Hana Bank in downtown Seoul on Thursday. (Yonhap)

South Korea's bourse operator on Thursday activated a sell-side sidecar for the benchmark Korea Composite Stock Price Index as the stock index plunged.

Program trading for the KOSPI-listed shares was suspended for five minutes at 10:16 a.m., according to the Korea Exchange.

After opening 1.82 percent lower, the KOSPI surrendered 265.65 points, or 4.67 percent, to 5,418.15 as of 10:16 a.m.

The index came under downward pressure following the Democratic Party's victory in the U.S. midterm elections, raising concerns over tighter regulations on artificial intelligence data centers.

A sell-side sidecar is triggered when the KOSPI 200 Futures Index falls 5 percent or more for at least one minute. (Yonhap)