KOSPI Plunges 7%, Falling Below 6,000 Mark

The KOSPI crashed more than 7 percent in a single day, breaking below 6,000 for the first time in about two months. The index opened more than 3 percent lower and extended its losses from the start of trading, triggering a sidecar — a mechanism to curb program selling — roughly an hour after the market opened. It was the first time the KOSPI had fallen below 6,000 since July 30.

As of 11:30 a.m., Samsung Electronics was trading in the 220,000-won range, down more than 8 percent, while SK hynix plunged 9 percent to the 1.45-million-won level. SK Square, SK hynix's largest shareholder, fell 12 percent.

The plunge is attributed to a series of overnight developments that rattled sentiment on semiconductor investment. Chinese chipmaker CXMT announced it would release next-generation DRAM products within the year, fueling concerns that Korean firms could cede their technological edge to Chinese rivals. Executives at Broadcom and Intel cited capital procurement as the biggest constraint on the expansion of the AI industry. "Share prices have risen so much that investors are highly sensitive to whether these levels can be sustained," said Park Seok-hyun, an analyst at Woori Bank. "Against that backdrop, even minor negative news is increasingly likely to shake stock prices."

The fallout also hit Wall Street, where semiconductor stocks sold off across the board, sending the Philadelphia Semiconductor Index down 2.67 percent.

The KOSDAQ was not spared from the slide. Opening 3 percent lower than the previous day, it extended its losses intraday and was hovering around 800, down 4 percent.