Market Structure · Breadth-of-Breadth
Breadth-of-Breadth
How broad is the bull? We read it two ways. First the absolute tape — of the ~500 S&P 500 names, how many are above their moving averages, making new highs vs lows, positive on the year. Then a relative-ratio diffusion index across 17 structural proxies for the rotation underneath. Together they catch a narrow bull while the index still looks fine.
Updated daily · data as of 2026-08-28 · 17 ratios live
Related Beta Instability — the up/down-beta read on the same pairs →
Broad-market participation (S&P 500, stock-level)
The relative ratios further down read rotation; this reads the tape directly — of the ~500 S&P 500 names, how many actually participate. A bull can be narrow even with the index near highs.
MA chips = price above its 20/50/200-day average. Green-200 but red-20 = a leader rolling over; green across = a laggard firming — that's the rotation. Our full universe (2753 names, incl. international + AI): 65% above 200d, median +8.5% YTD.
Rotation & concentration (relative-ratio diffusion)
Headline check — S&P 500 above a rising 50-day average, Nasdaq-100 not above a rising 50-day average. Participation broadly tracks the indices.
Participation grid
Breadth ratios — full detail
Every structural proxy, decomposed. State classifies each ratio's participation trend; the diffusion index weights them by importance. Core ratios (★) drive the confirmation score.
| Ratio | State | 21d | 63d | 252d | z-252 | %ile-252 | DD-252 | d/high |
|---|---|---|---|---|---|---|---|---|
| RSP/SPY★S&P 500 Equal-Weight Breadth | moderate broadening | -1.2% | +4.0% | -1.3% | +0.36 | 65 | -3.7% | 126 |
| QQQE/QQQ★Nasdaq-100 Equal-Weight Breadth | moderate broadening | -0.1% | +5.7% | -0.4% | +1.20 | 93 | -2.2% | 22 |
| QNXT/QTOP★Nasdaq Ex-Top-30 Breadth | strong broadening | +0.2% | +8.3% | -2.0% | +0.26 | 50 | -4.9% | 226 |
| XMAG/SPY★Ex-Mag-7 Breadth | moderate narrowing | -0.9% | +1.9% | +0.4% | +0.48 | 66 | -3.8% | 44 |
| SPXT/SPYEx-Tech S&P Breadth | failed recovery | -0.9% | +1.8% | -5.1% | -1.34 | 10 | -7.4% | 126 |
| QQXT/QQQNasdaq Ex-Tech Breadth | moderate broadening | -1.5% | +8.2% | -16.0% | -0.91 | 26 | -16.7% | 105 |
| IWM/SPY★Small-Cap Breadth | moderate narrowing | -2.5% | +0.1% | +5.3% | +0.48 | 62 | -6.5% | 44 |
| MDY/SPYMid-Cap Breadth | moderate narrowing | -3.1% | -0.3% | -2.8% | -0.72 | 27 | -6.5% | 125 |
| VXF/SPYExtended-Market Breadth | moderate narrowing | -1.4% | +0.8% | -1.0% | -0.03 | 43 | -5.0% | 44 |
| IWC/IWMMicro-Cap Breadth | strong broadening | +2.1% | +0.3% | +8.8% | +1.22 | 92 | -1.5% | 41 |
| HYG/LQD★Credit Breadth | strong broadening | +0.4% | +2.4% | +3.2% | +2.15 | 96 | -0.4% | 9 |
| SPHB/SPLV★High-Beta Breadth | moderate broadening | +6.2% | -6.7% | +33.9% | +1.20 | 82 | -9.3% | 48 |
| XLY/XLPConsumer Risk Breadth | moderate broadening | +4.3% | -6.4% | -7.0% | -0.80 | 29 | -15.5% | 205 |
| XLI/XLUCyclical Breadth | strong broadening | +3.8% | +5.9% | +13.7% | +1.63 | 95 | -3.1% | 14 |
| KBE/XLUFinancial Risk Breadth | strong broadening | +3.0% | +12.0% | +11.1% | +1.73 | 95 | -1.5% | 17 |
| IWO/IWNSmall Growth Breadth | moderate narrowing | +0.8% | -4.9% | -5.1% | -1.13 | 16 | -9.8% | 206 |
| IWF/IWDLarge Growth vs Value | moderate narrowing | +1.5% | -11.8% | -15.6% | -1.63 | 4 | -21.6% | 208 |
Tech-internal leadership (measured separately — concentration, not market breadth)
| Ratio | State | 21d | 63d | 252d | z-252 | %ile-252 |
|---|---|---|---|---|---|---|
| QTEC/QQXTNasdaq Tech vs Ex-Tech | moderate narrowing | +2.9% | -5.8% | +40.2% | +1.24 | 80 |
| SMH/XLKSemiconductor Leadership | moderate narrowing | -2.9% | -5.1% | +32.0% | +0.50 | 60 |
| IGV/XLKSoftware Participation | moderate broadening | +11.1% | +10.7% | -27.8% | -0.36 | 46 |
| FDN/XLKInternet Participation | moderate broadening | +4.0% | +6.8% | -23.9% | -0.77 | 30 |
| AIQ/XLKAI Participation | moderate broadening | +3.5% | -2.0% | +1.2% | -0.69 | 19 |
How to read it
Each ratio (numerator ÷ denominator, adjusted close) gets a full work-up — trend vs its 20/50/100/200-day averages, momentum over 5/21/63/126/252 days, a log z-score, percentile rank and relative drawdown — and is classified into a participation state. The diffusion index weights each ratio's state by importance; the composite score (0–100) blends the share above their 50-day average, the share with positive quarterly momentum, the diffusion, the median z and the core-ratio confirmation. Hidden breadth weakness fires when SPY/QQQ are positive but the score is weak — participation not confirming the tape.
For information and discussion only — a reading of market internals, not investment advice. Scores are relative and descriptive, on uncalibrated thresholds. Cross-read with Beta Instability, the Money Temperature regime and Cointegration.
FAQ · from the current data · as of 2026-08-28
Quick answers
What does Breadth-of-Breadth measure?
It reads participation two ways: the absolute tape (of the roughly 500 S&P 500 names, how many are above their moving averages, making new highs vs lows, positive on the year) and a relative-ratio diffusion index across roughly 16 structural proxies for the rotation underneath. Together they catch a narrow bull even while the index looks fine.
What is the current breadth verdict for the S&P 500?
As of 2026-08-28, the S&P 500 breadth verdict is "Broad" — 73% of names are above their 200-day average and the median stock is +11.5% year-to-date.
What is the Breadth-of-Breadth Score right now?
As of 2026-08-28, the Breadth-of-Breadth Score is 61 out of 100, reading as "Mixed participation".
How many structural ratios does Breadth-of-Breadth track?
As of 2026-08-28, the diffusion index tracks 17 structural ratios (of which 7 are core, confirmation-weighted).