When are circuit breakers triggered?

Circuit breakers (trading halts) are triggered in stages when the KOSPI or KOSDAQ index falls 8%, 15% or 20% or more from the previous trading day and stays there for 1 minute.

When stage 1 or 2 is triggered, all stock trading is halted for 20 minutes and then resumes with a 10-minute single-price auction; when stage 3 is triggered, stock trading ends for the day. The system is intended to give investors time to make calm judgments when share prices plunge.