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.
How to Read the Regime Sequence Strip
The third chart panel is a chronological strip of classified market regimes for the selected window. Each block is a completed or open regime segment; wider blocks lasted longer. Crash and calendar-year selections show every overlapping segment in that window. The live trailing-twelve-month view shows the recent sequence.
- Muted green (#1B4332) — Bull Expansion.
- Muted gold (#8A7344) — Bull Consolidation.
- Muted red (#7B2C2C) — Bear Liquidation.
- Muted slate blue (#3E4C5E) — Bear Basing.
- Grey (#888888) — Calibrating.
What Regime Duration Measures
A market regime is a classified phase of internal market health — Bull Expansion, Bull Consolidation, Bear Liquidation, Bear Basing, or Calibrating — derived from breadth participation on QQQ or SPY, not from the day’s price headline alone. Regime duration is how long the market has stayed in the current phase without shifting. The progress bar compares that length to the longest same-regime episode in the historical sample and reports the ratio as a percentage of the observed maximum, with historical mean and σ when available.
Regimes do not last forever. A phase that sits near its recorded maximum is objectively closer to a duration extreme than one that has barely begun. That comparison is a measurement of extension relative to history — not a forecast of the next price move.
How to Read Regime Transitions
The Regime Transitions section summarizes completed historical moves out of today’s current regime: which regimes followed it, how often, and the median sessions (or weeks) before the change. The optional full matrix expands that view to every from→to pair in the sample.
Frequencies describe the past sample only. They are not a prediction of what happens next, and the open (current) regime is excluded as a from-state until it completes.
- What is market breadth?
- Market breadth measures how many stocks in an index are participating in a move. A rising index with weak breadth means only a handful of large stocks are driving price — a common warning sign.
- What is the Distortion Score?
- The Distortion Score is Capital Trending (MCW) minus Symbols Trending (EW). A positive score means mega-caps are outperforming the average stock. A negative score means broad participation is stronger than the index headline suggests.
- Should I use daily or weekly breadth data?
- Daily breadth is best for short-cycle regime shifts and session-level context. Weekly breadth smooths noise and is better for structural regime analysis over months and years.
- What is regime duration?
- Regime duration is the number of trading sessions (or weeks) the market has remained in the same classified phase — such as Bull Expansion, Bear Liquidation, or Bull Consolidation — before shifting to a new regime. Breadth Signal derives these phases from participation metrics on QQQ and SPY, not from price trend alone.
- Why compare current duration to the historical maximum?
- Each regime type has a finite typical lifespan. When the current episode approaches the longest same-regime episode on record, duration-based structural exhaustion rises. This is an objective measurement of how extended the current phase is relative to history — not a price prediction.
- What does the transitions matrix show?
- The transitions list and full matrix report how often, in completed historical samples, one classified regime was followed by another, including frequency and median sessions before the change. These figures describe the past sample only — they are not a forecast of what happens next.
- 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.