Nasdaq Falls 1.4%, Philadelphia Semiconductor Index Enters Bear Market on July 17

U.S. stock indices fell sharply on July 17, with the Nasdaq Composite declining 1.4%, the S&P 500 dropping 1.01%, and the Dow Jones Industrial Average losing 0.77%. The Philadelphia Semiconductor Index fell 1.63% into bear territory, reflecting a decline of at least 20% from recent highs. Semiconductor stocks came under sustained selling pressure as China's AI startup Moonshot AI unveiled its latest model, Kimi K3, reportedly matching capabilities of OpenAI and Anthropic, raising market concerns about intensifying competition and potential diminishing returns on U.S. tech companies' AI investments.

For the week, the Philadelphia Semiconductor Index was down 10%, marking its worst week since April 2025, while the Nasdaq fell 2.9% and the S&P 500 dropped 1.5%. WTI crude oil surged 4.5% to $82.49 per barrel, while Brent crude rose 4.6% to $88.10, driven partly by escalating U.S.-Iran tensions.