How Breadth Score is calculated
BreadthMarket measures S&P 500 participation across 11 GICS sectors. Every sector has equal weight, regardless of its size or market capitalization.
The daily calculation
- Calculate SMA20. Average each stock's split-adjusted closing prices over the calculation session and the preceding 19 trading sessions.
- Compare the close. A stock counts as above SMA20 only when its close is strictly greater than that average. Equality does not count.
- Measure each sector. Divide the number above SMA20 by the number of eligible constituents in that sector, then multiply by 100.
Breadth Score = sum of the 11 sector percentages · 0–1100
Breadth Percent = Breadth Score ÷ 11 · 0–100%
Breadth Percent is also called Sector Balanced Breadth. Both express the same measure: a score of 660 equals 60%.
Eligibility and missing data
Each included stock needs all 20 genuine session closes. Exclusions require verified evidence of insufficient trading history or permanently ceased regular-way trading after acquisition or delisting. Ordinary missing prices prevent publication of the session; they are never filled in or treated as exclusions.
What does historical rank mean?
Historical rank is the percentage of readings in the stated period strictly below the latest reading. A rank of 80 means 80% of that period's readings were lower. Tied readings do not count as lower; the comparison includes the latest session.
Rank requires complete trading-session coverage and at least 20 observations. Breadth Score and Breadth Percent share the same rank. Ranks and regime labels describe participation; they do not predict returns.