On the 28th, the KOSPI index fell more than 8%, triggering a circuit breaker on the main board. It was the first circuit breaker in 10 trading days since on the 13th.
Korea Exchange (KRX) triggered a sell-sidecar (program trading halt) right after the open as the KOSPI and KOSDAQ indexes plunged, but as the wave of dumping did not ease, it halted trading itself about an hour after the open.
Korea Exchange (KRX) triggered a circuit breaker on the main board at 10:13:43 a.m. As a result, trading on the main board was halted for 20 minutes.
At the time it was triggered, the index was down 542.24 points (8.02%) from the previous day at 6,213.51.
It was the 14th circuit breaker on record and the eighth this year. With market volatility peaking in July, stabilizers have been tripping frequently. Of the eight circuit breakers this year, three were concentrated in July.
The exchange said the sharp KOSPI decline was linked to weakness in U.S. semiconductor-related stocks. On the previous day, China's top DRAM maker, CXMT, successfully listed, sending U.S. chip stocks sharply lower. News that the 5-year credit default swap (CDS) expense for Nvidia, the bellwether in AI chips, rose by a record margin also added to concerns.
In fact, the collapse of the semiconductor "two tops" that had been supporting the index is pulling the entire gauge down. Bellwether Samsung Electronics fell about 9%, slipping below 230,000 won, and SK hynix also dropped more than 10%, sinking to the low 1.6 million won level.
A circuit breaker is a system that halts all stock trading for 20 minutes if the KOSPI falls 8% or more from the prior close for at least one minute. Before trading resumes, orders are collected for 10 minutes and transactions are executed in a single-price auction.