On the morning of the 31st, shortly after the market opened, "buy-side circuit breakers" — which temporarily suspend the validity of program buy orders — were triggered simultaneously in both the KOSPI and KOSDAQ markets.

According to the Korea Exchange, a buy-side circuit breaker was activated in the securities market at 9:06:02 a.m. The price of futures based on KOSPI 200 (the highest-volume contract from the previous trading day) surged by 129.90 points (14.97%), from the base price of 867.60 points to 997.50 points. This met the trigger requirement of an increase of 5% or more sustained for at least one minute. Pursuant to Article 16 of the Securities Market Business Regulations, the validity of program buy orders in the securities market will be suspended for the next five minutes.

One second later, at 9:06:03 a.m., a buy-side circuit breaker was also triggered in the KOSDAQ market. The KOSDAQ 150 futures price rose by 99.40 points (9.33%), from the previous day's closing price of 1,064.40 points to 1,163.80 points, while the KOSDAQ 150 spot index also climbed 84.86 points (7.91%), from 1,072.42 points to 1,157.28 points. Accordingly, pursuant to Article 13 of the KOSDAQ Market Business Regulations and Article 14 of its Enforcement Detailed Rules, the validity of program buy orders in the KOSDAQ market will be suspended for the next five minutes.

The simultaneous activation of circuit breakers in both markets indicates that a strong rebound (buying) flow is entering the market in the early stages of trading.