The Nasdaq Composite opened sharply lower on September 14, 2026, and never recovered, closing down roughly 1% to 1.3% as a broad selloff swept through AI-related technology stocks. The trigger was uncomfortable: a public call from prominent AI executives urging a deliberate slowdown in the development of advanced AI models, citing what they described as serious safety risks.
What actually happened in the market
Nvidia bore the sharpest immediate pain among large-cap names, with shares falling between 3% and 3.7% in early trading, pushing the stock to its lowest level in three weeks. The Philadelphia SE Semiconductor Index, which tracks the broader chip sector, fell a more dramatic 5.5% to 6%.
AMD, Intel, Marvell, and Broadcom each declined between 5% and 8%.
The broader indices held up relatively better. The S&P 500 fell approximately 0.6% to 0.7%, while the Dow Jones Industrial Average slipped just 0.2% to 0.3%.
