What This Market Breadth Chart Shows
Most investors watch index price alone. This chart adds market internals: the percentage of stocks in QQQ or SPY that are in a confirmed uptrend, measured two ways. Symbols Trending (EW) treats every stock equally. Capital Trending (MCW) weights by market cap. When they diverge, the index can hide what the average stock is doing.
The Distortion Score (MCW minus EW)
The shaded area between the two participation lines is the Distortion Score. A positive spread means mega-caps are carrying the index while average stocks lag — often called a "hollow shell" rally. A negative spread means broad participation is stronger than the headline index suggests.
- Healthy Sync (spread under 5 points): EW and MCW broadly agree.
- Selective Strength (5–15 points): moderate dispersion — watch for widening.
- Severe Dispersion (15–25 points): structural decoupling between giants and the broad market.
- Extreme Fragility (25+ points): historically associated with elevated downside vulnerability.
QQQ vs SPY Breadth
QQQ tracks 100 large Nasdaq stocks; SPY tracks 500 S&P names across the broader economy. Because SPY is more diversified, it takes a larger coordinated move to trigger regime shifts. Toggle between indices above to compare Nasdaq concentration risk versus broad-market participation.
Daily vs Weekly Breadth Data
Use daily data for session-level context and short-cycle momentum. Use weekly data to filter noise and focus on multi-month structural regimes. We recommend one view at a time rather than overlaying both — each answers a different question.
Historical Crash Windows
Preset windows include the 2008 financial crisis, the 2020 COVID shock, and the 2022 tech contraction. Calendar-year buttons let you audit any year from 2007 forward. These views help you see how breadth behaved before, during, and after major drawdowns — independent of financial media narratives.
- Is this investment advice?
- No. Breadth Signal publishes quantitative research for education. Past breadth patterns do not guarantee future results. See our Terms of Service.
- How often is the data updated?
- Live readings update after each market session. Historical series refresh when our production data pipeline runs.
- Can I share or republish these charts?
- Yes — use the Download Chart or Copy Share Link buttons. When posting publicly, please credit Breadth Signal and link to breadthsignal.com/research/market-breadth-history.