A rare stock market crash signal that preceded several major downturns has been triggered on the S&P 500, raising concerns about the strength of the ongoing rally.
In this case, the Hindenburg Omen, a market breadth indicator designed to identify internal weakness beneath rising stock prices, has been activated 13 times over the past three months.
According to data shared by Bluekurtic Market Insights on August 11, this is only the third time since 1970 that the S&P 500 has recorded at least 13 Hindenburg Omen triggers within three months.
The warning comes as the benchmark index continues to trade near record highs, creating a divergence between headline performance and underlying market participation.
The Hindenburg Omen is a technical indicator that seeks to identify periods when a growing number of stocks are simultaneously making new 52-week highs and new 52-week lows while the broader market remains in an uptrend.
Such conditions can signal fragmentation beneath the surface of the market, where a handful of large stocks continue pushing indexes higher while weakness spreads across other areas.
What to look out for for next market crash
Market technicians generally place greater emphasis on clusters of signals rather than isolated occurrences. The latest reading stands out because the S&P 500 has now logged 13 triggers in three months, a level reached only twice before in the indicator’s history.
Analysis of the indicator shows only three historical instances in which the S&P 500 recorded 13 Hindenburg Omen triggers within three months.
The first occurred in January 1980. Over the following year, the index declined 13.4%, while the maximum drawdown reached 14.8%.
The second instance appeared in September 2018. Although the market initially remained resilient, the S&P 500 posted a maximum drawdown of 13.1% during the subsequent year.
The latest signal was recorded on August 1, 2026. Since it is still unfolding, forward performance data is not yet available.
While the sample size remains small, the historical record suggests that periods marked by unusually high concentrations of Hindenburg Omen signals have often been followed by increased volatility and meaningful market pullbacks.
Despite the stock market crash signal, the Hindenburg Omen does not guarantee a correction. The indicator has a history of false positives, with many warnings appearing during long-running bull markets that ultimately continued higher.
Mixed market outlook
Notably, as things stand, the current market backdrop is mixed. The S&P 500 has continued setting new highs in 2026, with some analysts projecting a record high of above 8,000 by year-end, supported by strong technology earnings.
However, market concentration remains elevated, with technology and communication services accounting for a significant share of the index.
Similar breadth warnings appeared earlier this year, coinciding with increased leverage and shifting market leadership beneath the surface.
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