Market breadth indicators track the number of advancing stocks (price up on the day), declining stocks (price down), and unchanged stocks across the entire exchange. Breadth gives a more complete picture of market health than looking at the headline index alone.
A rising index driven by only a handful of large-cap stocks while most small and mid-cap stocks are falling is described as a "narrow rally" — a potential red flag suggesting the broader market is not participating in the gains. Conversely, widespread advances with strong breadth readings suggest genuine broad-based optimism.
Common breadth indicators include the advance-decline line (a running total of advances minus declines), the advance-decline ratio, and the percentage of stocks trading above their 50-day or 200-day moving average.
At the CSE, breadth data published daily includes advancers, decliners, and unchanged stock counts. Comparing these against the ASPI direction quickly reveals whether a market move has broad support or is being driven by only a few large names.