What it is
The sidecar stops program trading orders briefly so that turmoil in futures does not spill into the cash market.
Triggers
If KOSPI 200 futures move 5% or more from the base price for one minute, KOSPI program trading orders are suspended for five minutes. On KOSDAQ it requires a 6%+ move in KOSDAQ 150 futures together with a 3%+ move in the KOSDAQ 150 index for one minute. It triggers once a day.
What to keep in mind
Unlike a circuit breaker, regular trading continues. A sidecar is itself a sign of extreme volatility.
This explanation is general information, not investment advice. Rules reflect September 2026 and may change; check official exchange and broker notices.