While the S & P 500 and Nasdaq 100 have both pushed to new all-time highs in November, market breadth indicators have mostly not confirmed those recent highs. While the trends for the major equity averages remain undeniably positive, the lack of breadth support suggests a painful reversal may be just around the corner. This chart shows the S & P 500 on a closing basis along with three common measures of market breadth: the cumulative advance-decline line, the percent of stocks above their 50-day moving average, and the Bullish Percent Index. Note how all three of the breadth indicators shown have actually made lower highs in November, despite the S & P 500’s move above the 6,000 level. Market breadth indicators like these are equal-weighted, meaning they simply count the number of stocks fulfilling a certain requirement. This often can provide a compelling counterpoint to the cap-weighted indexes like the S & P 500 which are so heavily overweight the mega cap growth stocks. The advance-decline line has been trending lower since mid-October, telling us that over time there are more stocks closing lower than closing higher. We can also see that about 55% of the S & P 500 members are currently above their 50-day moving average, and that’s down from about 82% in late September. The bottom panel shows the Bullish Percent Index, which is a breadth indicator based on point & figure charts. The change in that indicator over the last six weeks tells us that about 20% of the S & P 500 members have registered a sell signal on their point & figure charts! To be clear, longer-term measures of breadth are still in decent shape. This chart shows the percent of stocks above their 200-day moving average, as well as the percent of stocks above their 50-day moving average as we quoted above. We can see that about 70% of S & P 500 members are above their 200-day moving average, and that reading has been fairly stable through 2024. So the market uptrend is certainly supported by long-term breadth measures. Levels to watch How do we approach a market with robust long-term breadth but weaker short-term breadth conditions? I would argue that it comes down to risk management and focusing on a “line in the sand” at which point we agree to reassess long positions. The S & P 500 continues to make higher lows, but a push below 5,850 would break that pattern which has been in place since August. For me, the most important potential support level remains at 5,650. Any drop below that threshold would mean a lower low, a break of the 50-day moving average, and a failure to hold the 38.2% retracement based on the August to November rally. If and when we would break below 5,650, I would definitely be revisiting the bullish thesis into year-end 2024. Healthy bull market phases tend to show strong breadth characteristics, as most stocks are following the overall bullish market trend. But when the market starts to make new higher highs on weaker breadth conditions, I start to wonder whether the market is not nearly as healthy as the indexes would have us believe. -David Keller, CMT marketmisbehavior.com DISCLOSURES: (None) All opinions expressed by the CNBC Pro contributors are solely their opinions and do not reflect the opinions of CNBC, NBC UNIVERSAL, their parent company or affiliates, and may have been previously disseminated by them on television, radio, internet or another medium. THE ABOVE CONTENT IS SUBJECT TO OUR TERMS AND CONDITIONS AND PRIVACY POLICY . THIS CONTENT IS PROVIDED FOR INFORMATIONAL PURPOSES ONLY AND DOES NOT CONSITUTE FINANCIAL, INVESTMENT, TAX OR LEGAL ADVICE OR A RECOMMENDATION TO BUY ANY SECURITY OR OTHER FINANCIAL ASSET. THE CONTENT IS GENERAL IN NATURE AND DOES NOT REFLECT ANY INDIVIDUAL’S UNIQUE PERSONAL CIRCUMSTANCES. THE ABOVE CONTENT MIGHT NOT BE SUITABLE FOR YOUR PARTICULAR CIRCUMSTANCES. BEFORE MAKING ANY FINANCIAL DECISIONS, YOU SHOULD STRONGLY CONSIDER SEEKING ADVICE FROM YOUR OWN FINANCIAL OR INVESTMENT ADVISOR. Click here for the full disclaimer.