[COVER STORY] Black Thursday: KOSPI plunges 7% amid AI spending fears

Korean stocks plunged 7.57 percent in Seoul Thursday as concerns over AI spending and the semiconductor outlook triggered a broad sell-off. The KOSPI closed at 5,554.22, while nearly 400 trillion won in market capitalization was erased. Foreign investors sold 3.6 trillion won in shares, and market safeguards were triggered during the session. The sell-off followed hotter-than-expected U.S. inflation data and rising Treasury yields, prompting an emergency meeting by financial authorities.

The KOSPI had fallen 40.4 percent from its June 19 peak of 9,385 points, while its seven-session decline since Oct. 6 erased more than 1,100 trillion won in market capitalization.

A sell-side sidecar was triggered at 9:07 a.m., followed by a Level 1 circuit breaker at 12:38 p.m.; the sidecar activates after a qualifying KOSPI 200 futures decline of at least 5 percent, while the circuit breaker requires an 8 percent benchmark drop for one minute.

Samsung Electronics fell 9.48 percent to 210,000 won, and SK hynix dropped 11.06 percent to 1.262 million won.

The Kosdaq fell 7.65 percent to close at 760.82, with a sell-side sidecar at 9:12 a.m. and a Level 1 circuit breaker at 12:23 p.m.

Foreign selling extended to eight consecutive trading sessions, while institutional and retail investors recorded net purchases of 1.69 trillion won and 1.29 trillion won, respectively.

Published Oct 15, 2026 4:27 pm KST

Updated Oct 15, 2026 5:53 pm KST

7-session rout erases over $745 bil. in market cap

The benchmark KOSPI is displayed in the dealing room of Hana Bank in Seoul, Thursday. The index closed at 5,554.22, down 7.57 percent from the previous session. Korea Times photo by Shim Hyun-chul

Korean stocks plunged 7.57 percent and shed nearly 400 trillion won ($297.7 billion) in market capitalization Thursday, amid concerns over the sustainability of artificial intelligence (AI) spending and the outlook for the semiconductor sector.

The benchmark KOSPI closed at 5,554.22, down 7.57 percent. A sell-side sidecar was triggered at 9:07 a.m., marking the 27th activation this year, followed by a Level 1 circuit breaker at 12:38 p.m.

A sell-side sidecar is triggered when the most actively traded KOSPI 200 future falls at least 5 percent from the previous session for one minute. A Level 1 circuit breaker kicks in when the benchmark index drops at least 8 percent from the previous close for one minute.

Foreign investors dumped 3.6 trillion won worth of shares, extending their net selling streak to eight consecutive trading sessions. Institutional and retail investors made net purchases of 1.69 trillion won and 1.29 trillion won, respectively, stepping in to scoop up shares at bargain prices.

Heavy selling weighed on market heavyweights. Samsung Electronics fell 9.48 percent to close at 210,000 won, while SK hynix dropped 11.06 percent to 1.262 million won.

SK Square, LG Energy Solution, Samsung Electro-Mechanics and Hyundai Motor also fell 10.21 percent, 4.62 percent, 15.36 percent and 5.74 percent, respectively.

The tech-heavy Kosdaq was also hit hard, plunging 7.65 percent to close at 760.82. A sell-side sidecar was triggered at 9:12 a.m., followed by a Level 1 circuit breaker at 12:23 p.m.

"KOSPI is now down 40.4 percent from its June 19 peak of 9,385 points, approaching the median decline of 43.7 percent recorded during seven previous market crises, including Black Monday in 1987, the Asian financial crisis in 1997, the dot-com crash in 2000 and the global financial crisis in 2008," said Lee Kyoung-min, an analyst at Daishin Securities.

Over seven consecutive trading sessions since Oct. 6, KOSPI has plunged about 20 percent, wiping out over 1,100 trillion won in market capitalization.

Graphic by Cho Sang-won

Thursday's sell-off was attributed to worsening investor sentiment after U.S. consumer price data for September came in hotter than expected, fueling concerns over further monetary tightening.

The yield on the 10-year U.S. Treasury note subsequently climbed above 5.3 percent, raising concerns about higher borrowing costs for AI infrastructure companies that have relied heavily on debt to finance expensive chips, power systems and equipment.

Shares of CoreWeave, which rents out AI computing capacity to businesses, plunged 15.46 percent on Wednesday (local time), while rival Nebius tumbled 10.08 percent. Oracle, which has been aggressively expanding its data center investments, slid 8.83 percent, while AI server maker Dell Technologies sank 11.27 percent.

The pressures were compounded by deteriorating investor sentiment in the Korean market, which extended its losing streak to seven sessions, according to Han Ji-young, an analyst at Kiwoom Securities.

"The upcoming third-quarter earnings season will be another key test for market-leading stocks to dispel concerns over AI, as they did in the second quarter," Han said. "Volatility is likely to remain elevated as investors assess the results."

Yun Jung-in, CEO of Fibonacci Asset Management Global in Singapore, said foreign investors may continue selling Korean stocks in the near term, but it is too early to conclude that they are pulling out of the Korean market for the long term.

"If interest rates stabilize and foreign investors return, beaten-down blue-chip stocks could lead a rebound," Yun said. "We view the current correction as an opportunity to selectively buy stocks with solid earnings prospects."

Financial authorities held an emergency meeting later in the day in an effort to ease market concerns. They said the sell-off appeared excessive in terms of the pace of the decline and investor trading flows. They also stressed that Korea's key industries continue to post solid earnings on the back of their global competitiveness, while the country's economic fundamentals remain robust.

KOSPI rout deepens retail losses, fuels forced selling fears

KOSPI falls for 6th session, barely holds above 6,000

周四，受人工智能支出和半导体前景担忧引发的抛售潮影响，韩国股市在首尔暴跌7.57%。韩国综合股价指数（KOSPI）收于5554.22点，市值蒸发近400万亿韩元。外国投资者抛售了3.6万亿韩元的股票，市场安全措施在交易时段内被触发。此次抛售潮是由于美国通胀数据高于预期以及美国国债收益率上升，促使金融监管机构召开紧急会议。

韩国综合股价指数（KOSPI）自 6 月 19 日的峰值 9385 点以来下跌了 40.4%，自 10 月 6 日以来的七个交易日下跌使其市值蒸发了超过 1100 万亿韩元。

上午 9:07 触发了卖方侧车操作，随后在下午 12:38 触发了 1 级熔断机制；侧车操作在 KOSPI 200 期货下跌至少 5% 后激活，而熔断机制则要求基准指数下跌 8% 并持续一分钟。

三星电子股价下跌 9.48% 至 210,000 韩元，SK 海力士股价下跌 11.06% 至 1262 万韩元。

韩国创业板指数下跌7.65%，收于760.82点，上午9:12触发卖方侧车操作，下午12:23触发一级熔断机制。

外国投资者连续八个交易日抛售，而机构投资者和散户投资者分别录得净买入1.69万亿韩元和1.29万亿韩元。

发布于2026年10月15日下午4:27（韩国标准时间）

更新于2026年10月15日下午5:53（韩国标准时间）

七日暴跌导致市值蒸发超过7450亿美元

周四，首尔韩亚银行交易大厅内展示着韩国综合股价指数（KOSPI）。该指数收于5554.22点，较前一交易日下跌7.57%。图片由《韩国时报》沈贤哲拍摄。

周四，由于对人工智能 (AI) 支出的可持续性和半导体行业的前景感到担忧，韩国股市暴跌 7.57%，市值蒸发近 400 万亿韩元（2977 亿美元）。

韩国综合股价指数（KOSPI）收于5554.22点，下跌7.57%。上午9点07分触发卖方追加指令，这是今年第27次触发该指令，随后于下午12点38分启动一级熔断机制。

当交投最活跃的KOSPI 200期货价格较前一交易日下跌至少5%并持续1分钟时，卖方触发侧车指令。当基准指数较前一交易日收盘价下跌至少8%并持续1分钟时，一级熔断机制启动。

外国投资者抛售了价值3.6万亿韩元的股票，连续第八个交易日净卖出。机构投资者和散户投资者分别净买入1.69万亿韩元和1.29万亿韩元，趁机以低价买入股票。

大量抛售拖累了市场巨头。三星电子股价下跌9.48%，收于21万韩元；SK海力士股价下跌11.06%，收于126.2万韩元。

SK Square、LG Energy Solution、三星电机和现代汽车的股价也分别下跌了10.21%、4.62%、15.36%和5.74%。

科技股为主的韩国创业板指数（Kosdaq）也遭受重创，暴跌7.65%，收于760.82点。上午9点12分触发卖方侧车操作，随后于下午12点23分触发一级熔断机制。

大信证券分析师李京民表示：“韩国综合股价指数（KOSPI）目前较6月19日9385点的峰值下跌了40.4%，接近此前七次市场危机期间43.7%的平均跌幅，其中包括1987年的黑色星期一、1997年的亚洲金融危机、2000年的互联网泡沫破裂和2008年的全球金融危机。”

自 10 月 6 日以来，韩国综合股价指数 (KOSPI) 连续七个交易日暴跌约 20%，市值蒸发超过 1100 万亿韩元。

插图：赵相元

周四的抛售潮归因于美国9月份消费者价格数据超出预期，导致投资者情绪恶化，加剧了人们对货币政策进一步收紧的担忧。

随后，10 年期美国国债收益率攀升至 5.3% 以上，引发了人们对人工智能基础设施公司借贷成本上升的担忧，这些公司严重依赖债务来为昂贵的芯片、电力系统和设备融资。

向企业出租人工智能计算能力的CoreWeave公司股价周三（当地时间）暴跌15.46%，其竞争对手Nebius股价也下跌10.08%。一直在积极扩大数据中心投资的甲骨文公司股价下跌8.83%，而人工智能服务器制造商戴尔科技公司股价则下跌11.27%。

Kiwoom Securities 分析师韩智英表示，韩国市场投资者情绪恶化加剧了这些压力，韩国市场已连续七个交易日下跌。

韩表示：“即将到来的第三季度财报季将再次考验市场领头羊股票，以消除人们对人工智能的担忧，就像第二季度一样。投资者在评估财报结果的过程中，市场波动性可能会持续高企。”

新加坡斐波那契资产管理全球公司首席执行官尹正仁表示，外国投资者短期内可能会继续抛售韩国股票，但现在就断定他们会长期撤出韩国市场还为时过早。

“如果利率企稳，外国投资者回归，此前遭受重创的蓝筹股可能会引领反弹，”Yun表示。“我们认为目前的调整是选择性买入那些盈利前景稳健的股票的好机会。”

为缓解市场担忧，金融监管机构当天晚些时候召开紧急会议。他们表示，从下跌速度和投资者交易量来看，此次抛售似乎过度。他们还强调，凭借其全球竞争力，韩国重点产业持续保持稳健盈利，同时韩国经济基本面依然强劲。

韩国综合股价指数暴跌加剧零售业损失，引发被迫抛售担忧。

KOSPI指数连续第六个交易日下跌，勉强守住6000点上方。