market
essential
Market Breadth
How many stocks participate in a move — broad participation supports sustainable rallies.
Market breadth measures how widely a rally or decline is distributed across stocks (advancers vs decliners, new highs vs new lows, sector participation).
Narrow rallies driven by a few mega-caps can hide weakness underneath. Swing Edge surfaces breadth-style context on sector momentum pages and uses distribution-day counts as a per-stock breadth proxy.