#Gate股票7x24小时交易 South Korea’s stock market triggers a circuit breaker: KOSDAQ plunges on June 23 as Korean stocks fall sharply!

On June 23, sentiment in the Asia-Pacific stock markets weakened. Korea’s stock market opened lower across the board and kept sliding. During the session, the KOSDAQ index’s intraday decline broke above 5%, panic selling intensified, and the Korea Exchange urgently activated the Sidecar circuit breaker mechanism, pausing programmatic trading across the whole market for 5 minutes to curb a stampede caused by algorithmic orders.

This round of selloff was not driven by a sudden negative catalyst. The key reason was profit-taking after the earlier AI chip rally became overheated. Previously, Samsung and SK Hynix led Korean stocks higher for an extended period, with the index repeatedly setting new highs. Foreign investors and retail investors built up large unrealized gains. Overnight, the U.S. tech sector pulled back broadly. Overseas funds were the first to sell Korea’s equity heavyweight semiconductor names, and after the market opened, the selling pressure spread quickly. The decline in KOSDAQ’s small- and mid-cap growth stocks was further amplified.

According to market data, semiconductors, power batteries, and the automotive sector became the main forces behind the rout. SK Hynix fell by more than 6.6%, Samsung Electronics dropped by nearly 5.5%, and LG Energy Solution and Hyundai Motor also tumbled sharply. Most individual stocks fell broadly, and only just over a hundred tickers closed up. In the morning session, foreign investors net sold more than 2 trillion won. Combined with high-leverage ETFs and programmatic sell orders, this amplified index volatility and directly triggered circuit-breaker risk controls.

The programmatic pause mechanism launched this time only restricts algorithmic trading. Manual buying and selling by retail investors is not affected. The 5-minute cooling-off period temporarily eased panic, but it was unable to reverse the downward trend. Industry analysts noted that the market value of the Korean stock market is highly concentrated in semiconductors, and the level of retail margin leverage remains high as well—making the market prone to sharp rallies and sharp crashes. Regulators have been paying attention to the market risks posed by high-leverage products, and stabilization measures may be introduced next to alleviate extreme short-term volatility.

In the short term, there is still pressure for a pullback in the technology sector. Foreign investors’ “exit” sentiment has not fully dissipated. Korean stocks may continue to trade sideways and adjust, and investors should remain alert to the risk of continued pullbacks being released by tightly held, high-positioned sectors.