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 2026-10-09 · 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): 49% above 200d, median +4.7% 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.
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% | -4.2% | -3.1% | -1.57 | 5 | -8.0% | 155 |
| QQQE/QQQ★Nasdaq-100 Equal-Weight Breadth | strong narrowing | -2.1% | -3.0% | -4.0% | -1.43 | 9 | -7.0% | 51 |
| QNXT/QTOP★Nasdaq Ex-Top-30 Breadth | strong narrowing | -3.0% | -4.4% | -11.2% | -1.77 | 8 | -11.7% | 164 |
| XMAG/SPY★Ex-Mag-7 Breadth | moderate narrowing | -1.4% | -2.9% | -0.5% | -0.88 | 22 | -5.7% | 73 |
| SPXT/SPYEx-Tech S&P Breadth | strong narrowing | -2.3% | -4.0% | -5.7% | -1.90 | 4 | -10.2% | 155 |
| QQXT/QQQNasdaq Ex-Tech Breadth | strong narrowing | -5.7% | -6.2% | -19.0% | -1.66 | 5 | -24.2% | 134 |
| IWM/SPY★Small-Cap Breadth | strong narrowing | -5.6% | -8.5% | -2.3% | -1.75 | 5 | -12.9% | 73 |
| MDY/SPYMid-Cap Breadth | strong narrowing | -3.2% | -6.0% | -3.6% | -1.96 | 1 | -10.3% | 154 |
| VXF/SPYExtended-Market Breadth | strong narrowing | -3.1% | -5.5% | -4.5% | -2.15 | 2 | -9.0% | 73 |
| IWC/IWMMicro-Cap Breadth | failed recovery | -0.7% | -0.5% | +5.1% | +0.76 | 73 | -2.3% | 13 |
| HYG/LQD★Credit Breadth | strong broadening | +0.1% | +1.6% | +5.3% | +1.87 | 96 | -0.3% | 9 |
| SPHB/SPLV★High-Beta Breadth | strong broadening | +8.4% | +11.6% | +35.0% | +1.72 | 96 | -2.4% | 4 |
| XLY/XLPConsumer Risk Breadth | moderate narrowing | -0.1% | -1.8% | -12.7% | -0.88 | 20 | -17.1% | 234 |
| XLI/XLUCyclical Breadth | moderate broadening | +1.4% | +3.1% | +17.3% | +0.98 | 84 | -5.3% | 10 |
| KBE/XLUFinancial Risk Breadth | moderate narrowing | -4.8% | +1.1% | +16.8% | +0.73 | 75 | -7.8% | 10 |
| IWO/IWNSmall Growth Breadth | recovery attempt | +1.0% | -2.2% | -8.6% | -1.04 | 17 | -10.4% | 235 |
| IWF/IWDLarge Growth vs Value | moderate broadening | +5.1% | +2.5% | -13.9% | -0.56 | 33 | -17.0% | 237 |
| Ratio | State | 21d | 63d | 252d | z-252 | %ile-252 |
|---|---|---|---|---|---|---|
| QTEC/QQXTNasdaq Tech vs Ex-Tech | strong broadening | +8.3% | +7.2% | +39.5% | +1.48 | 93 |
| SMH/XLKSemiconductor Leadership | recovery attempt | +0.2% | -6.2% | +27.2% | +0.45 | 58 |
| IGV/XLKSoftware Participation | moderate broadening | +3.6% | +10.7% | -29.1% | -0.39 | 48 |
| FDN/XLKInternet Participation | moderate narrowing | -1.8% | -0.1% | -22.6% | -0.97 | 22 |
| AIQ/XLKAI Participation | strong narrowing | -1.7% | -1.0% | -5.9% | -1.86 | 8 |
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 2026-10-09
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 2026-10-09, the S&P 500 breadth verdict is "Narrow-to-mixed" — 53% of names are above their 200-day average and the median stock is +6.2% year-to-date.
As of 2026-10-09, the Breadth-of-Breadth Score is 27 out of 100, reading as "Hidden breadth weakness".
As of 2026-10-09, the diffusion index tracks 17 structural ratios (of which 7 are core, confirmation-weighted).