S&P 500, Nasdaq end sharply lower as revived AI doubts ignite tech selloff - Reuters

The S&P 500 and Nasdaq closed sharply lower as renewed doubts about artificial intelligence weighed on technology shares, according to Reuters. The pullback reflects a shift in sentiment rather than a single catalyst: after a long stretch in which AI enthusiasm powered major indexes, investors appear to be reassessing how quickly those investments will translate into earnings.

The Nasdaq's technology-heavy composition makes it especially sensitive to this kind of reappraisal, while the S&P 500's broader base means the weakness was not confined to one corner of the market. When the largest companies stumble, their sheer index weight can drag on headline performance even if other sectors hold steadier.

What to watch: whether the selloff proves a short-term sentiment swing or the start of a deeper rotation away from AI-linked names. Upcoming earnings guidance, capital-spending plans from major tech firms, and any commentary on AI revenue timelines will likely shape the narrative. For long-term investors, days like this are a reminder that thematic enthusiasm can cut both ways—and that index-level moves often mask wide differences beneath the surface.