# US stock market technical deterioration

> Developing situation record from CLSTR: https://clstr.news/situations/us-stock-market-technical-deterioration
> Updated: 2026-10-11T17:01:00.000Z. Sources: 8. Developments: 2.

US equity markets have experienced a period of technical deterioration characterized by weakening market breadth and narrowing leadership.

In mid-September, indicators suggested a potential transition toward a market stress regime. While headline indices like the S&P 500 and Nasdaq saw price bounces, internal weakness was evident; for example, the Nasdaq recorded 164 new lows against only 33 new highs, and only about 23.5% of its stocks remained above their 20-day simple moving average.

By October, data from Morgan Stanley highlighted a significant divergence in performance. While the S&P 500 remained near record levels due to the heavy weighting of a few large-cap companies, the broader market showed strain. Approximately 54% of Russell 3000 companies had fallen at least 20% from their June highs, and the percentage of S&P 500 companies trading above their 200-day moving averages dropped from roughly 75% to below 50%.

## Timeline

### 2026-10-11: US Stock Market Breadth Declines Amid Volatility

Market breadth is narrowing as over half of Russell 3000 companies have dropped 20% from June highs, despite the S&P 500 remaining near records due to large-cap dominance.

4 sources. https://clstr.news/cluster/us-stock-market-breadth-declines-amid-volatility

### 2026-09-13: Nasdaq and S&P 500 show signs of technical deterioration

US stock market internals show severe deterioration, with Nasdaq and S&P 500 breadth approaching washout levels as new lows significantly outpace new highs.

4 sources. https://clstr.news/cluster/nasdaq-and-sp-500-show-signs-of-technical-deterioration

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Cite as: US stock market technical deterioration. CLSTR, https://clstr.news/situations/us-stock-market-technical-deterioration