U.S. stocks ended sharply lower on Wednesday as hotter-than-expected September inflation altered expectations for the Federal Reserve’s interest-rate path. The Nasdaq bore the brunt of the selling as investors reassessed valuations for technology and artificial intelligence companies whose growth prospects are particularly sensitive to higher borrowing costs.

Inflation Data Changes the Rate Outlook

The September inflation reading was the central catalyst behind the market decline. U.S. inflation increased more than expected, prompting investors to increase bets that the Federal Reserve may need to raise interest rates further to contain persistent price pressures.

The shift in expectations was particularly damaging for growth-oriented equities. Higher interest rates can increase financing costs and reduce the present value assigned to future corporate earnings, making highly valued technology companies more vulnerable when bond yields and rate expectations move higher.

Nasdaq Bears the Brunt of the Selling

The technology-heavy Nasdaq Composite dropped 1.88%, substantially underperforming the broader market. The S&P 500 declined 1.11%, while the Dow Jones Industrial Average was comparatively resilient, falling just 0.09%.

The divergence reflected the concentration of selling in technology and AI-linked companies. Several of the strongest-performing areas of the 2026 market rally faced renewed pressure as investors adjusted to the prospect of a more restrictive monetary environment.

AI Stocks Face Renewed Valuation Pressure

Oracle was among the most notable decliners, falling 8.8%. AI-infrastructure companies CoreWeave and Nebius also suffered substantial losses, declining 15% and 10%, respectively.

The moves demonstrate how quickly changes in interest-rate expectations can affect companies associated with the AI investment cycle. These businesses are operating in areas where capital requirements and expectations for future growth are important considerations, making them particularly sensitive to changes in financing conditions.

Bank Earnings Add Another Market Variable

The inflation shock arrived as investors were also assessing the beginning of another major U.S. bank earnings period. Bank of America shares slipped after the bank reported lower third-quarter profit, adding another source of differentiation within the financial sector.

The combination of inflation data and corporate earnings leaves markets facing two competing signals: resilient corporate activity in some areas and renewed monetary-policy pressure from inflation. For investors globally, including those exposed to U.S. technology markets, the next focus will be whether inflation continues to exceed expectations and how Federal Reserve officials respond to the changing price environment.

Going forward, the durability of the selloff will depend heavily on incoming inflation and economic data, as well as further corporate earnings results. The sixth consecutive decline in the chip index also warrants attention as semiconductor and AI-related valuations adjust to higher-rate expectations. A sustained increase in inflation pressures could extend the rotation away from rate-sensitive growth stocks, while evidence of moderation could reduce some of the pressure on technology markets.