Wall Street closed the week on a sour note, with the S&P 500 and Nasdaq sliding as concerns over Big Tech's massive AI spending sprees reached a fever pitch. A report suggesting a delay in OpenAI's initial public offering sent shockwaves through the technology sector, compounding existing anxieties about frothy valuations.

Investors are now demanding tangible proof that the trillions of dollars pouring into artificial intelligence infrastructure will translate into real revenue and profit. The selloff was broad but concentrated in AI-exposed names, with chipmakers taking a particularly hard hit, even as other corners of the market like healthcare showed resilience.

Specifically, the S&P 500 ended lower as semiconductor stocks tumbled, a decline only partially offset by a rally in Moderna shares. While most of Wall Street edged higher on the final trading day, sinking AI stocks dragged the market into negative territory for the week.

This pivot toward profitability over promise marks a potential turning point for the AI boom. Companies that have been rewarded for aggressive capital expenditure may now face greater scrutiny from investors who want to see a clear path to monetization.

Analysts caution that while the long-term thesis for AI remains intact, the current environment suggests a period of consolidation and valuation correction may be ahead for the sector's biggest spenders.