The U.S. equity market is experiencing an unusual divergence, with major technology and artificial intelligence stocks declining sharply while the broader market continues to advance. According to The Kobeissi Letter, the Nasdaq 100 lost approximately $4 trillion in market capitalization over 25 days, even as the S&P 500 excluding AI-related exposure reached a record high. The contrasting performance raises questions about market concentration, technology valuations and the underlying strength of the broader equity market.

Nasdaq 100 Faces a Sharp Correction as Technology Stocks Retreat

The Nasdaq 100 has come under substantial selling pressure, with The Kobeissi Letter reporting that the index erased approximately $4 trillion in market capitalization over a 25-day period. The post also indicated that AI-related stocks declined by more than 13% during October, reflecting a significant reversal in investor sentiment toward companies associated with the artificial intelligence investment cycle.

The accompanying chart illustrates the divergence between the Nasdaq 100 and the S&P 500 excluding Information Technology and Communication Services. At the latest displayed readings, the Nasdaq 100 stood approximately 9.18% lower, while the broader ex-sector index showed a gain of approximately 4.79%. These chart readings are separate from the post’s rounded October performance figures and reflect the specific series and measurement window displayed.

The weakness in technology shares is particularly significant because major semiconductor, software and digital infrastructure companies have played an influential role in driving U.S. equity-market gains. When these companies experience substantial corrections, the impact can extend beyond the technology sector through their significant representation in major indexes and institutional portfolios.

The Broader S&P 500 Shows Strength Beneath the Surface

While technology shares have struggled, the S&P 500 excluding Information Technology and Communication Services has reportedly reached a record high. The Kobeissi Letter estimates that this measure gained approximately 8% during October, suggesting that companies outside these two sectors have provided substantial support to the broader market.

This divergence highlights an important characteristic of capitalization-weighted indexes: the performance of a relatively small group of influential companies can have a disproportionate effect on headline returns. Removing the Information Technology and Communication Services sectors provides a different perspective on market participation, although it is not equivalent to removing only AI-related companies. Both sectors contain businesses with activities beyond artificial intelligence, meaning the comparison should be interpreted as a broader sector-based measure.

The distinction also challenges the assumption that weakness in large technology stocks necessarily indicates weakness across the entire U.S. equity market. Strength in financials, industrials, healthcare, consumer-related companies and other sectors can support index performance even when major technology constituents are declining.

Valuations and Market Concentration Create a New Investment Landscape

The divergence between technology stocks and the broader market raises questions about how investors are assessing future earnings growth and valuations. Companies associated with AI have benefited from substantial expectations surrounding data-center expansion, semiconductor demand, cloud computing and enterprise adoption. However, elevated expectations can make share prices particularly sensitive to changes in earnings forecasts, capital expenditure plans and anticipated returns on investment.

A correction in AI-related shares does not necessarily indicate that the long-term commercial potential of artificial intelligence is weakening. Rather, it may reflect a reassessment of the prices investors are willing to pay for expected growth. At the same time, the relative strength of other sectors suggests that capital allocation within the equity market may be becoming more diversified.

For investors in Israel and globally, this development is relevant because U.S. technology companies have significant influence over international equity benchmarks and global investment portfolios. A sustained separation between technology performance and the broader market could change sector leadership, affect portfolio concentration and influence international capital flows.

Going forward, investors will monitor technology earnings, AI-related capital expenditure, semiconductor demand, market breadth and the performance of sectors outside technology. If the broader S&P 500 continues advancing while AI stocks remain under pressure, the market may experience a prolonged rotation in leadership rather than a uniform downturn. Conversely, if weakness spreads into financials, industrials and other sectors, the current divergence could give way to broader market instability. The central question is whether the technology correction represents a valuation adjustment within an otherwise resilient equity market or the beginning of a more extensive repricing of U.S. stocks.