Market Structure · Beta Instability

Market X-Ray

The chart can be fine while participation breaks down underneath. The X-Ray measures it directly — upside beta (on up-days), downside beta (on down-days), asymmetry and instability — across the key structure pairs and 343 names in our indices. Detecting the rotation before price makes it obvious.

vs S&P 500 35% losing upside participation, 39% gaining downside fragility

vs Nasdaq-100 42% losing upside participation, 26% gaining downside fragility

Updated daily · data as of 2026-07-31 · Participation fragile — fragility rising beneath the surface

Latest read The Generals Have Followed Their Troops — the breadth warning becomes price confirmation →

Toolboxes Daily Read → Beta Instability Breadth-of-Breadth · 51 Mixed participation → Ratio-Quality → Divergence Scanner → Alert Stack → Regime Baselines → Anomaly Score → Directory →

The pairs we watch — full scores

Each pair, decomposed on up-days and down-days separately. These are the published "Troops Leaving Before the Generals" set — now confirmed by price in "The Generals Have Followed Their Troops".

SMH / QQQ fragile

Semiconductor leadership vs Nasdaq

Upside β1.76

Downside β1.95

Asymmetry-0.19

Particip.0.90

horizon	21d	63d	126d	252d
up β	1.95	1.76	1.76	1.73
down β	1.45	1.96	1.95	1.92

β-z +2.05instab 51 partic 64fragil 96 conv A -1.15 · accelerating-up

downside-beta expansionnegative beta asymmetry

XSD / QQQ fragile

Equal-weight semis vs Nasdaq

Upside β1.81

Downside β2.23

Asymmetry-0.42

Particip.0.81

horizon	21d	63d	126d	252d
up β	2.38	1.87	1.81	1.94
down β	2.25	2.29	2.23	2.12

β-z +2.06instab 59 partic 85fragil 99 conv A -2.16 · reversing-up

downside-beta expansionnegative beta asymmetry

XSD / SPY decoupling

Equal-weight semis vs market

Upside β2.69

Downside β2.37

Asymmetry+0.32

Particip.1.13

horizon	21d	63d	126d	252d
up β	7.18	3.76	2.69	2.69
down β	1.08	2.25	2.37	2.35

β-z +2.59instab 100 partic 100fragil 86 conv A +0.93 · accelerating-up

downside-beta expansion

IWM / SPY distribution

Small-cap participation

Upside β1.03

Downside β1.06

Asymmetry-0.03

Particip.0.97

horizon	21d	63d	126d	252d
up β	0.87	0.74	1.03	1.27
down β	0.31	0.93	1.06	1.12

β-z -2.45instab 60 partic 28fragil 31 conv A -0.39 · flat

negative beta asymmetrybeta-adjusted underperformanceupside participation deteriorating (sharp)

RSP / SPY decoupling

S&P 500 equal-weight participation

Upside β0.60

Downside β0.80

Asymmetry-0.21

Particip.0.74

horizon	21d	63d	126d	252d
up β	-0.52	0.28	0.60	0.69
down β	0.52	0.74	0.80	0.76

β-z -2.96instab 66 partic 2fragil 51 conv A -2.49 · accelerating-down

upside-beta collapsenegative beta asymmetryupside participation deteriorating (sharp)

HYG / SPY distribution

Credit confirmation

Upside β0.25

Downside β0.21

Asymmetry+0.03

Particip.1.17

horizon	21d	63d	126d	252d
up β	0.10	0.19	0.25	0.28
down β	0.22	0.18	0.21	0.18

β-z -0.58instab 15 partic 18fragil 52 conv A -0.66 · accelerating-down

upside-beta collapsebeta-adjusted underperformance

ARKK / QQQ decoupling

Speculative-growth appetite

Upside β1.49

Downside β1.26

Asymmetry+0.22

Particip.1.18

horizon	21d	63d	126d	252d
up β	1.81	1.44	1.49	1.38
down β	1.53	1.21	1.26	1.45

β-z -2.35instab 49 partic 59fragil 4 conv A +1.68 · improving-but-stalling

downside-beta expansion (sharp)

Participation breadth — by index (vs S&P 500)

lake 2397 names 36% losing upside participation, 38% gaining downside fragility rubin 123 names 11% losing upside participation, 63% gaining downside fragility halo 100 names 25% losing upside participation, 43% gaining downside fragility euro-ai 65 names 22% losing upside participation, 35% gaining downside fragility aw25 38 names 58% losing upside participation, 13% gaining downside fragility agentic 32 names 56% losing upside participation, 19% gaining downside fragility etfs 14 names 50% losing upside participation, 36% gaining downside fragility

Want a specific name? Open the X-Ray Directory → — search, sort and open any of 2769 names on the full toolbox vs SPY & Nasdaq.

How to read it

For each pair (asset vs benchmark), returns are split into the benchmark's up-days and down-days. Upside β is participation in rallies; downside β is vulnerability in selloffs; asymmetry (up − down) and the participation ratio (up ÷ down) say whether an asset captures more upside than downside. Read across 21 / 63 / 126 / 252 days: a sharp drop at the short horizon while the long looks fine is the early warning.

For information and discussion only — a reading of market internals, not investment advice. Scores are relative and descriptive. Cross-read with the Money Temperature regime.