Is the rally broad or narrow?
Indexes are dominated by their biggest names. Breadth counts how many stocks are actually participating — the healthiest markets rise with most stocks above their averages.
% of stocks above their 50-day and 200-day averages
Advance-decline line (cumulative)
New 52-week highs vs lows
How to read breadth
Above 70% of stocks over their 200-day average is a broad, healthy bull market; readings under 30% have historically marked washed-out conditions near important lows. A rising index with a falling percentage — or a falling advance-decline line — means fewer stocks are carrying the market, a classic warning sign late in a rally.
Computed from the daily closes of every S&P 500 (or S&P 1500) member after each US session.
Frequently asked questions
What is market breadth?
Market breadth measures how many stocks are participating in a move. Common gauges are the percentage of stocks above their 50-day or 200-day moving average, the advance-decline line, and new 52-week highs versus lows.
Why can the S&P 500 rise while most stocks fall?
The S&P 500 is weighted by market capitalisation, so a handful of trillion-dollar companies can move the index more than hundreds of smaller members combined.
What is a good level for the percent of stocks above the 200-day average?
There is no single number, but above 60-70% signals broad strength, and below 20-30% signals broad weakness that often precedes a rebound.