Skip to main content
Breadth answers one question: are most stocks moving with the index, or is a small group of names doing all the work? A market that goes up on five mega-caps is more fragile than a market that goes up on four hundred names. Breadth tells you which kind of day it was.

​
The metrics you’ll see

​
Advances / Declines (A/D)

How many stocks went up vs down. Net A/D = advancers minus decliners.
  • Strongly positive (e.g., +300) = broad rally, real participation
  • Strongly negative = broad sell-off
  • Near zero on a big index move = only a few names moved the index

​
% above moving average

What fraction of stocks are above their 1W / 1M / 3M / 6M / 1Y MA. Stacked across timeframes:
  • % above 1W MA = short-term momentum
  • % above 1M MA = trend health
  • % above 1Y MA = secular regime
The shorter the MA, the more sensitive — when % above 1W drops sharply but % above 1Y stays high, you’re in a tactical pullback inside a structural uptrend.

​
RSP / SPY ratio

Equal-weight S&P (RSP) divided by cap-weighted (SPY).
  • Falling RSP/SPY = mega-caps carrying the index, narrow leadership
  • Rising RSP/SPY = broad participation, healthy rally

​
”Deteriorating breadth”

When you read this in a recap, it usually means one of:
  • A/D net is shrinking even as the index goes up
  • % above 1M or 3M MA is falling toward 50%
  • RSP/SPY is dropping (concentration is increasing)
Why it matters: deteriorating breadth often precedes corrections. The index can stay green for weeks while internals rot, and then catch up suddenly.

​
The breadth cockpit

The Equities page’s Market Breadth panel condenses all of this into five dimensions, each shown with its current value, percentile vs its own history, and a sparkline: The panel synthesizes the five into one state — HEALTHY (broad participation confirms the trend), THRUST (a momentum ignition off a low), WASHOUT (capitulation readings, the contrarian zone), DIVERGENCE (index up while internals rot — the classic pre-correction pattern), or NARROW (a few names doing all the work) — with a one-line read naming what’s driving it — state first, then the evidence, then an under-the-surface outlier only when a group clears a threshold (a washed-out slice at p10–, or a pocket of strength at p95+). The banner dots summarize the same tally the state uses, in three tiers: saturated green/red only at a true 2-year extreme (p80+/p20–), amber for a mild lean, gray for neutral. Click any dimension to open it as a full chart.

​
The Breadth Explorer

The cockpit’s Decompose → link answers the follow-up question: whose breadth? The Explorer splits the same % - above - 50-day measure by sector, size bucket, theme, or factor basket, showing each group’s contribution to the recent move and a two-year quilt of every group’s breadth vs its own history — so “breadth deteriorated” becomes “Semiconductors are washed out at p2 while Financials sit at p97.”

​
Where you see it

  • The Equities page’s Market Breadth cockpit (above) — the live panel
  • Equity Internals section of the Daily Recap
  • Market Pulse breadth tile — the pulse consumes the cockpit’s state directly