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 2026-10-06 · 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 (3661 names, incl. international + AI): 50% above 200d, median +5.6% 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.
The index breakout lacks confirmation from participation proxies.
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 | -4.0% | -4.1% | -4.2% | -1.80 | 2 | -8.4% | 152 |
| QQQE/QQQ★Nasdaq-100 Equal-Weight Breadth | strong narrowing | -3.6% | -3.2% | -4.8% | -1.61 | 7 | -7.2% | 48 |
| QNXT/QTOP★Nasdaq Ex-Top-30 Breadth | washout | -6.4% | -5.1% | -13.5% | -2.05 | 4 | -13.2% | 251 |
| XMAG/SPY★Ex-Mag-7 Breadth | moderate narrowing | -1.7% | -3.0% | -0.8% | -0.94 | 20 | -5.7% | 70 |
| SPXT/SPYEx-Tech S&P Breadth | washout | -3.4% | -4.6% | -7.2% | -2.29 | 1 | -11.1% | 152 |
| QQXT/QQQNasdaq Ex-Tech Breadth | strong narrowing | -9.1% | -7.6% | -21.7% | -1.94 | 1 | -25.6% | 131 |
| IWM/SPY★Small-Cap Breadth | strong narrowing | -6.0% | -8.3% | -1.8% | -1.53 | 8 | -12.2% | 70 |
| MDY/SPYMid-Cap Breadth | strong narrowing | -3.5% | -5.2% | -3.5% | -1.77 | 4 | -9.7% | 151 |
| VXF/SPYExtended-Market Breadth | strong narrowing | -3.4% | -5.2% | -3.9% | -1.77 | 6 | -8.2% | 70 |
| IWC/IWMMicro-Cap Breadth | failed recovery | -0.8% | -0.7% | +6.6% | +1.02 | 81 | -1.8% | 10 |
| HYG/LQD★Credit Breadth | strong broadening | +0.8% | +2.5% | +5.7% | +2.12 | 100 | -0.0% | 6 |
| SPHB/SPLV★High-Beta Breadth | strong broadening | +10.0% | +13.4% | +40.2% | +1.99 | 100 | -0.1% | 1 |
| XLY/XLPConsumer Risk Breadth | moderate broadening | +0.1% | -0.5% | -12.1% | -0.74 | 31 | -16.2% | 231 |
| XLI/XLUCyclical Breadth | moderate broadening | +2.0% | +4.3% | +18.0% | +1.30 | 91 | -3.4% | 7 |
| KBE/XLUFinancial Risk Breadth | moderate narrowing | -3.7% | +4.6% | +15.9% | +0.97 | 80 | -6.1% | 7 |
| IWO/IWNSmall Growth Breadth | recovery attempt | +0.7% | -3.7% | -7.4% | -0.97 | 19 | -10.1% | 232 |
| IWF/IWDLarge Growth vs Value | moderate broadening | +6.8% | +3.0% | -11.5% | -0.32 | 45 | -15.5% | 234 |
| Ratio | State | 21d | 63d | 252d | z-252 | %ile-252 |
|---|---|---|---|---|---|---|
| QTEC/QQXTNasdaq Tech vs Ex-Tech | strong broadening | +13.4% | +10.1% | +47.2% | +1.75 | 99 |
| SMH/XLKSemiconductor Leadership | moderate broadening | +3.3% | -4.3% | +32.1% | +0.76 | 75 |
| IGV/XLKSoftware Participation | failed recovery | -1.6% | +7.8% | -32.1% | -0.60 | 37 |
| FDN/XLKInternet Participation | strong narrowing | -5.5% | -1.7% | -25.1% | -1.31 | 9 |
| AIQ/XLKAI Participation | strong narrowing | -3.5% | -3.9% | -6.3% | -2.37 | 1 |
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 2026-10-06
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 2026-10-06, the S&P 500 breadth verdict is "Narrow-to-mixed" — 53% of names are above their 200-day average and the median stock is +7.5% year-to-date.
As of 2026-10-06, the Breadth-of-Breadth Score is 27 out of 100, reading as "Hidden breadth weakness".
As of 2026-10-06, the diffusion index tracks 17 structural ratios (of which 7 are core, confirmation-weighted).