What happened to KOSPI trading when the Korea Exchange activated a sell-side sidecar on Friday?

The Korea Exchange suspended program trading for KOSPI-listed shares for five minutes, beginning at 10:04 a.m. The sidecar was activated as the index plunged.

Why did investor sentiment weaken as the KOSPI fell on Friday?

Renewed concerns about whether the artificial intelligence boom could be sustained weighed on investors after Wall Street shares retreated overnight. Alphabet plunged more than 12 percent after its third-quarter revenue missed market expectations.

What threshold triggers a KOSPI sell-side sidecar?

The trigger is a fall of 5 percent or more in the KOSPI 200 Futures Index that lasts for at least one minute.

KRX activates sell-side sidecar for KOSPI on sharp fall

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Summary

The Korea Exchange (KRX) activated a sell-side sidecar for the KOSPI in South Korea on Friday as the index plunged. Program trading for KOSPI-listed shares was suspended for five minutes at 10:04 a.m. The index fell 277.75 points, or 4.68 percent, to 5,661.7 as of 10:06 a.m. after opening 2.99 percent lower, amid investor concerns about the sustainability of the artificial intelligence boom following overnight Wall Street losses.

Key Facts

The KOSPI 200 Futures Index must fall 5 percent or more for at least one minute to trigger a sell-side sidecar.
Alphabet fell more than 12 percent overnight after its third-quarter revenue missed market expectations.
The KOSPI is the benchmark Korea Composite Stock Price Index.

By Yonhap

Published Oct 30, 2026 10:20 am KST

The benchmark KOSPI and Kosdaq indices are displayed at a dealing room of Hana Bank in Seoul, Friday. Yonhap

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

Program trading for the KOSPI-listed shares was suspended for five minutes at 10:04 a.m., according to the Korea Exchange (KRX).

After opening 2.99 percent lower, the KOSPI fell 277.75 points, or 4.68 percent, to 5,661.7 as of 10:06 a.m.

The index came under downward pressure following overnight losses on Wall Street, as renewed concerns over the sustainability of the artificial intelligence (AI) boom weighed on investor sentiment.

Overnight, Wall Street shares retreated, with Google parent Alphabet plunging more than 12 percent after its third-quarter revenue missed market expectations.

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

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