Equities • Quantitative
Market Breadth: Advance/Decline, 200-DMA & Breadth Thrusts
How the A/D line, 52-week new highs/lows, and the Zweig Breadth Thrust signal powerful market inflection points.
Author: CMD Wire Institutional Research
Updated: August 2026 • 6 min read
1. What Is Market Breadth?
Market Breadth evaluates the underlying health and internal participation of an equity index by analyzing how many individual component stocks are participating in an upward or downward price trend, rather than relying solely on cap-weighted index prices.
2. Essential Breadth Indicators
- Advance-Decline Line (A/D Line): The cumulative running total of advancing stocks minus declining stocks. A rising index with a declining A/D line creates a bearish breadth divergence.
- Percentage of Stocks Above 200-Day Moving Average: Measures long-term secular market health across broad market universes.
- New Highs vs. New Lows: Compares stocks hitting 52-week highs versus 52-week lows.
3. Breadth Thrusts: Powerful Quantitative Buy Signals
A Breadth Thrust occurs when market momentum shifts violently from extreme pessimism to overwhelming broad-based buying within a compressed timeframe:
The Zweig Breadth Thrust (ZBT):
Occurs when the 10-day exponential moving average of the Advance/Total Issues ratio surges from below 0.40 to above 0.615 within 10 trading sessions. Historically, a confirmed ZBT has preceded positive 12-month forward S&P 500 returns with a 100% historical win rate.
Occurs when the 10-day exponential moving average of the Advance/Total Issues ratio surges from below 0.40 to above 0.615 within 10 trading sessions. Historically, a confirmed ZBT has preceded positive 12-month forward S&P 500 returns with a 100% historical win rate.