Market Structure · 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 2026-10-08 · 17 ratios live
Related Beta Instability — the up/down-beta read on the same pairs →
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 (3666 names, incl. international + AI): 48% above 200d, median +4.2% YTD.
Headline check — S&P 500 above a rising 50-day average, Nasdaq-100 above a rising 50-day average. Participation is NOT confirming the indices — hidden weakness.
Headline index strength is not confirmed by internal participation.
Market participation is severely narrow — headline strength concentrated in a small group of leaders.
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 | strong narrowing | -2.6% | -3.4% | -3.3% | -1.57 | 5 | -8.0% | 154 |
| QQQE/QQQ★Nasdaq-100 Equal-Weight Breadth | strong narrowing | -2.4% | -2.6% | -4.3% | -1.58 | 7 | -7.2% | 50 |
| QNXT/QTOP★Nasdaq Ex-Top-30 Breadth | strong narrowing | -3.7% | -3.9% | -12.2% | -1.96 | 4 | -12.3% | 163 |
| XMAG/SPY★Ex-Mag-7 Breadth | strong narrowing | -1.9% | -3.0% | -0.8% | -1.01 | 18 | -5.8% | 72 |
| SPXT/SPYEx-Tech S&P Breadth | strong narrowing | -2.3% | -3.4% | -6.4% | -1.97 | 4 | -10.4% | 154 |
| QQXT/QQQNasdaq Ex-Tech Breadth | strong narrowing | -5.7% | -4.7% | -20.1% | -1.72 | 3 | -24.5% | 133 |
| IWM/SPY★Small-Cap Breadth | strong narrowing | -5.9% | -8.5% | -1.8% | -1.73 | 5 | -12.8% | 72 |
| MDY/SPYMid-Cap Breadth | strong narrowing | -3.4% | -5.8% | -3.2% | -1.96 | 1 | -10.3% | 153 |
| VXF/SPYExtended-Market Breadth | strong narrowing | -3.8% | -5.8% | -4.1% | -2.29 | 2 | -9.2% | 72 |
| IWC/IWMMicro-Cap Breadth | failed recovery | -0.6% | -0.3% | +5.3% | +0.98 | 79 | -1.9% | 12 |
| HYG/LQD★Credit Breadth | strong broadening | +0.4% | +1.7% | +5.1% | +1.79 | 95 | -0.5% | 8 |
| SPHB/SPLV★High-Beta Breadth | strong broadening | +5.4% | +6.7% | +36.1% | +1.62 | 93 | -3.5% | 3 |
| XLY/XLPConsumer Risk Breadth | strong narrowing | -1.5% | -4.3% | -12.8% | -1.06 | 11 | -17.9% | 233 |
| XLI/XLUCyclical Breadth | moderate broadening | +2.0% | +1.9% | +17.9% | +1.03 | 85 | -4.9% | 9 |
| KBE/XLUFinancial Risk Breadth | moderate narrowing | -2.0% | +2.0% | +17.1% | +0.92 | 78 | -6.5% | 9 |
| IWO/IWNSmall Growth Breadth | strong narrowing | -0.7% | -4.5% | -9.2% | -1.34 | 7 | -11.3% | 234 |
| IWF/IWDLarge Growth vs Value | moderate broadening | +4.4% | +0.2% | -13.3% | -0.57 | 32 | -17.0% | 236 |
| Ratio | State | 21d | 63d | 252d | z-252 | %ile-252 |
|---|---|---|---|---|---|---|
| QTEC/QQXTNasdaq Tech vs Ex-Tech | strong broadening | +7.5% | +4.3% | +42.6% | +1.51 | 93 |
| SMH/XLKSemiconductor Leadership | moderate broadening | +0.3% | -6.8% | +29.9% | +0.57 | 64 |
| IGV/XLKSoftware Participation | moderate broadening | +2.1% | +11.3% | -31.1% | -0.55 | 41 |
| FDN/XLKInternet Participation | moderate narrowing | -2.8% | +0.2% | -24.1% | -1.14 | 16 |
| AIQ/XLKAI Participation | strong narrowing | -2.9% | -3.0% | -6.7% | -2.33 | 2 |
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 2026-10-08
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.
As of 2026-10-08, the S&P 500 breadth verdict is "Narrow-to-mixed" — 51% of names are above their 200-day average and the median stock is +6.8% year-to-date.
As of 2026-10-08, the Breadth-of-Breadth Score is 25 out of 100, reading as "Hidden breadth weakness".
As of 2026-10-08, the diffusion index tracks 17 structural ratios (of which 7 are core, confirmation-weighted).