The upside/downside ratio is a market breadth indicator that depicts the relationship between the volume of advancing and declining stocks on a stock exchange. This indicator is commonly used by investors to determine the market's momentum at any particular period. The upside/downside ratio is a variation of the advance-decline ratio (ADR), which analyzes the number, rather than the volume, of stocks that closed higher to the number of stocks that closed lower than their previous day's closing prices.