> ## Documentation Index
> Fetch the complete documentation index at: https://auramarkets.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Breadth

> Are most stocks moving with the index, or is a small group doing all the work?

**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.

## Where you see it

* **Equity Internals** section of the [Daily Recap](/macro/daily-recap)
* **Market Pulse** breadth tile
* The [Indices](/indices/overview) page surfaces a US breadth panel