 Advance–decline line

The advance–decline line is a stock market technical indicator used by investors to measure the number of individual stocks participating in a market rise or fall.As price changes of large stocks can have a disproportionate effect on capitalization weighted stock market indices such as the S&P 500, the NYSE Composite Index, and the NASDAQ Composite index, it can be useful to know how broadly this movement extends into the larger universe of smaller stocks.