📈 Market Breadth Signals
Market Internals Series — 2/5
# 📈 Market Breadth Signals
## 🎯 Beyond the Headlines
The S&P 500 can rally while the average stock declines. Market cap weighting creates illusions. Breadth indicators strip away the illusion and reveal the truth.
Understanding breadth separates traders who follow narratives from traders who follow money.
## 📊 Essential Breadth Indicators
**1. Advance-Decline Line**
The cumulative sum of advancing minus declining stocks. The foundation of breadth analysis.
**2. Advance-Decline Ratio (ADR)**
Advancing Issues ÷ Declining Issues. Readings above 2 indicate broad strength; below 0.5 indicate broad weakness.
**3. NYSE New Highs vs. New Lows**
The number of stocks hitting 52-week highs minus those hitting 52-week lows. Expanding new highs confirm bull markets; expanding new lows warn of bear markets.
**4. % of Stocks Above Moving Averages**
Typically the 50-day and 200-day. Readings above 70% suggest overbought conditions; below 30% suggest oversold.
—
## 📊 Learn With Titan: Breadth Toolkit
| Indicator | Best For | Thresholds |
|———–|———-|————|
| A/D Line | Trend confirmation | Watch divergences |
| ADR | Short-term extremes | >2 overbought, <0.5 oversold |
| New Highs/Lows | Momentum | NH/NL > 100 healthy |
| % Above 50 MA | Intermediate term | >70% extended, <30% washed out |
| McClellan Oscillator | Short-term timing | +100 overbought, -100 oversold |
---
## 🔍 The McClellan Oscillator
**The Calculation**
A smoothed measure of daily breadth using exponential moving averages of Net Advances. The formula:
- 19-day EMA of Net Advances
- 39-day EMA of Net Advances
- Oscillator = (19 EMA) - (39 EMA)
**Interpretation**
- **+100 to +150**: Market overbought, caution warranted
- **-100 to -150**: Market oversold, bounce likely
- **Zero line crossovers**: Trend change signals
- **Breadth thrusts**: Strong moves from deep negative to positive
---
## 📈 The Summation Index
The McClellan Summation Index is the cumulative McClellan Oscillator. It provides intermediate-term breadth perspective.
**Key Levels**
- Above +1000: Strong bull market breadth
- Below -1000: Serious bear market conditions
- Crosses of zero: Major trend changes
**Breadth Thrusts**
When the Summation Index rises rapidly from deeply negative to strongly positive, it signals powerful accumulation. These thrusts often mark the beginning of significant rallies.
---
## 🎯 Breadth in Practice
**Bull Market Characteristics**
- A/D Line trending higher
- Consistent new highs outpacing new lows
- 60-80% of stocks above 200-day MA
- McClellan Oscillator spends more time positive than negative
**Bear Market Characteristics**
- A/D Line trending lower
- New lows expanding
- Less than 25% of stocks above 200-day MA
- McClellan Oscillator negative for extended periods
---
## ⚠️ Breadth Traps
**The Cap-Weighted Illusion**
Seven stocks can carry the S&P 500 higher while 493 stagnate. Always check breadth before trusting index moves.
**Sector Rotation**
Declining breadth can indicate rotation, not deterioration. Money moves from growth to value, tech to energy—not out of the market entirely.
**Late-Cycle Strength**
Breadth often deteriorates before price peaks. The last rally is frequently the narrowest and most dangerous.
---
## 🏆 Key Takeaways
- ✅ Market breadth reveals what's happening beneath index levels
- ✅ Multiple breadth indicators provide confirmation
- ✅ Breadth divergences warn of trend exhaustion
- ✅ Breadth thrusts signal powerful accumulation phases
---
*← Previous: The Advance-Decline Line | Continue to Part 3: Sector Rotation Dynamics →*
