Market Breadth

How to tell whether a rally is broad or carried by a few giants, the main breadth measures, and real readings from our data at the 2025 and 2026 turns.

Is everybody joining in?

An index like the S&P 500 is market-cap weighted, so a handful of giant companies can push it higher even while most stocks fall. Market breadth measures how many stocks are participating in a move. Broad participation suggests a healthy trend. Narrow participation, where the index rises on the backs of a few leaders, can be a warning sign.

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