Nasdaq Has Its Worst Day in Three Months and CoreWeave Falls 15.5%; KOSPI Drops as Much as 7.77% the Next Morning
A hotter US inflation print and souring sentiment toward AI financing sent the Nasdaq down 1.9% on Oct. 14, its biggest fall in three months, Reuters reported, with the SOX chip index down 4.2% and CoreWeave down 15.5%. In Seoul on Oct. 15 the KOSPI fell as much as 7.77% by 10:30 a.m., Korea JoongAng Daily reported.
Investors are now repricing the AI trade through its funding, not its demand, according to Reuters' Jamie McGeever, who wrote on Wednesday, October 14 that sentiment toward AI financing "is souring. Rapidly." US stocks fell sharply that day on surprisingly strong September inflation data and those financing worries, Reuters reported, with the Nasdaq down 1.9%, its biggest fall in three months. The inflation figures put a Federal Reserve rate hike later this month back on the table, according to Reuters.
Wall Street on October 14
The Nasdaq Composite closed down 1.88% at 26,692.87 and the S&P 500 fell 1.11% to 7,718.94, CNBC reported. Reuters said the SOX chip index fell 4.2%, down for a sixth day in its longest losing streak in nearly two years. CoreWeave fell 15.5%, Dell 11%, and Oracle and Marvell 9%, according to Reuters.
US AI-related corporate bonds fell sharply, many to new lows, Reuters reported. CoreWeave's 9.75% bond maturing in 2031 yielded 16% and fell to a new low in price, and Oracle's 4.9% bond maturing in 2033 registered a record low, according to the column.
The same day, Gartner forecast that more than $3.5 trillion of AI infrastructure spending could be exposed to impairment by the end of 2030 if AI providers keep their current pace of capital spending. It also predicted that cost pressure and a lack of a differentiating business model will force over 80% of neocloud providers to cease independent operations by 2030. Those are Gartner's projections.
Dan Ives of Yorkville Ives argued in a note that "rates are a financing question, not a demand question," CNBC reported. "What would change our view is a demand signal, not a rate signal," he said.
Seoul and Tokyo on October 15
The KOSPI opened 5.59% lower at 5,673.01 on Thursday and was down 7.77% at 5,539.51 as of 10:30 a.m. Seoul time, Korea JoongAng Daily reported. Sell-side sidecar curbs were triggered at 9:07 a.m. on the KOSPI and 9:12 a.m. on the KOSDAQ, according to the paper. Foreign investors were net sellers of 1.92 trillion won ($1.4 billion) of shares as of 10:30 a.m., it said. The BBC put the KOSPI 7.6% lower in morning trading. These are intraday levels, not closes.
Stock moves varied by outlet and time. JoongAng Daily, in a report published at 11:34 a.m. Seoul time, had Samsung Electronics down 9.05% and SK hynix down 10.71%. CNBC reported SK Hynix down more than 10% and Samsung down 7.1%, and SoftBank Group down 7.9% in Tokyo, along with Advantest down 6.9%.
JoongAng Daily also cited concern about memory supply from China's CXMT and US consumer prices that rose 3.7% from a year earlier in September. Park Yeon-ju of Mirae Asset Securities told the paper the biggest factor was concern over AI returns, "as Anthropic's third-quarter revenue growth slowed from the previous quarter." She added that the fall was "excessive relative to earnings." We cover the Anthropic figures attendees reported separately.
Broadcom's Hock Tan had warned on October 12 that capital may be AI's biggest constraint. Seoul's index had rebounded early on October 14 after five sessions of chip selling.
Limits
- Seoul and Tokyo figures are intraday snapshots at different times and were still moving when this was written; no closing levels are included.
- Reuters' McGeever column is analysis; the attribution of the selloff to AI financing versus inflation is the outlets' and analysts' framing.
- Gartner's impairment and neocloud figures are forecasts.
- Korea JoongAng Daily says its article was translated from Korean with AI tools and edited by its newsroom; quotes are as published in English by the paper.
- AP and Yonhap market pages were not used; the Bloomberg and Financial Times pages could not be opened.
Sources
- Reuters via Investing.com: Trading Day: Tech melt (October 14, 2026)
- CNBC: SK Hynix shares plunge 10% amid Asia tech rout (October 14, 2026 ET)
- Korea JoongAng Daily: Kospi plunges over 7% as AI doubts, U.S. rate fears hit Seoul (October 15, 2026)
- BBC News: Anthropic flags revenue surge to investors ahead of stock market debut (October 14, 2026)
- Gartner: Over $3.5 Trillion of AI Infrastructure Spending Could Be Exposed to Impairment by the End of 2030 (October 14, 2026)
- Times of AI: Anthropic Q3 revenue, attendees say (October 15, 2026)
- Times of AI: Broadcom's Hock Tan on capital (October 13, 2026)
- Times of AI: KOSPI chip selloff and rebound (October 12–14, 2026)