Market Breadth
Participation under the surface — how many stocks are advancing — the structural health behind an index move.
- · 45.2% above 50-day, 63.5% above 200-day
- · McClellan negative at -35.5
- — Neither broad strength nor washout — trade the sector table, not the index: own what participates.
- — Keep index exposure modest; mixed breadth is where whipsaws live.
- — Watch the leadership ratios (RSP/SPY, IWM/SPY) for the tell on which way this resolves.
Divergence Detector
Does the army confirm the general? Index highs vs the A/D line and % above 50-day
No divergence test active — the index is 2.3% below its 1-year high. Watch for breadth to LEAD on the next approach of the highs.
Gold = index (left) · green = cumulative advance/decline line of the panel (right). Healthy: they make highs together. Warning: index up, A/D line flat or down.
McClellan Oscillator
EMA19 − EMA39 of ratio-adjusted net advances
The momentum of breadth. Extremes matter most: deep negative readings (−70 and below) cluster near tradeable lows; a fast swing from deep negative to strongly positive is a thrust — the market’s highest-conviction buy pattern.
% Above 50-Day
Share of the panel in short-term uptrends, last 12 months
A mean-reverting oscillator with teeth at the edges: above 80% = overbought BUT bullish (initiation strength); below 20% = washout, historically far closer to bottoms than to the start of new downtrends.
Leadership Check
Equal-weight vs cap-weight (RSP/SPY -0.6% over 3m) · small caps vs large (IWM/SPY -3.9%)
Mixed leadership — neither a broad advance nor an extreme mega-cap squeeze. Watch which way the ratios resolve.
Sector Participation
SPDR sector ETFs vs their own trend + constituent breadth from the panel, sorted by 1-month return
| Sector | 1m return | > 50d | > 200d | Panel % > 50d | 1-month momentum |
|---|---|---|---|---|---|
| XLE Energy | +5.7% | ● | ● | 100% (n=3) | |
| XLC Communication | +2.2% | ● | ● | 85.7% (n=7) | |
| XLV Health Care | -0.4% | ● | ● | 64.7% (n=17) | |
| XLP Staples | -1.8% | ● | ● | 50% (n=10) | |
| XLF Financials | -2.1% | ● | ● | 33.3% (n=18) | |
| XLK Technology | -3.4% | ● | ● | 61.1% (n=18) | |
| XLB Materials | -3.5% | ● | ● | 50% (n=2) | |
| XLRE Real Estate | -4.4% | ● | ● | 50% (n=2) | |
| XLY Discretionary | -4.7% | ● | ● | 10% (n=10) | |
| XLU Utilities | -5% | ● | ● | 0% (n=3) | |
| XLI Industrials | -8.5% | ● | ● | 14.3% (n=14) |
In a Mixed or Narrowing regime this table IS the trade: own what participates, avoid what’s broken. Green dots on both trend columns with strong panel breadth = the sectors carrying the market.
Global Breadth
Country ETFs vs their 200-day average — is the advance global or a US-only story?
Global confirmation strengthens any US signal; the US rallying alone while the world sits below trend is a narrower story than the index chart suggests. 12/18 markets above their 200-day.
The 60-second version
An index is a headline; breadth is the story under it. The S&P can make new highs carried by five mega-caps while the average stock is already in a downtrend — and every major top in modern history looked exactly like that months before the index broke. This page measures participation directly: every indicator here is computed from the raw daily closes of a ~100-stock panel — advance/decline line, McClellan oscillator, Zweig thrust, % above moving averages, new highs and lows — then cross-checked against equal-weight and small-cap leadership, sector participation, and 18 country markets.
Why traders who ignore breadth still get paid by it
- It's a topping clock, not a timing tool — breadth divergences don't call the day — they call the PHASE. Index highs without A/D confirmation historically precede tops by weeks to months. The detector above runs that test continuously so you don't have to.
- Washouts are gifts — fewer than 20% of stocks above their 50-day is panic-level participation. It marks tradeable lows far more reliably than any price pattern — the famous breadth-thrust signals (Zweig >0.615, McClellan snapping positive) all fire out of this zone.
- It tells you WHAT to trade, not just when — in a narrow tape the sector participation table matters more than the index chart: own the green rows, avoid the red. Equal-weight lagging cap-weight means stock-picking is fighting uphill — size accordingly.
- Confirmed strength persists — when the index makes highs AND the A/D line, equal-weight and small caps confirm, drawdowns stay shallow — that's the regime where buying dips is a strategy rather than a hope.
Methodology & honesty
The panel is the current S&P 100 membership (~100 names, sector- tagged), so breadth history carries mild survivorship bias — fine for reading participation NOW, which is what breadth is for. The A/D line and McClellan oscillator are computed on this panel, not the full NYSE: levels differ from StockCharts’ NYSE versions, but the shape, zero-crossings and divergences — the tradeable content — behave the same, and 100 mega/large caps ARE the index for practical purposes (cap-weighting means they decide where the S&P goes). New highs/lows use a 52-week lookback within 0.5%. Country and sector reads use liquid ETFs against their own 200-day averages. Everything refreshes every 15 minutes from raw Yahoo closes — nothing here is a scraped summary statistic.
In the MTS framework
Breadth is Motion’s structural-health layer — where the volatility page reads how the tape moves, this page reads how many soldiers are marching with it. Use it as a filter on every other Motion signal: momentum buys are stronger when participation confirms; a seasonal or cycle-based long into a flagged divergence deserves half size; and a washout reading turns the crash playbook from “short the breakdown” to “stalk the thrust”.