The Breadth Thrust Indicator is a market momentum indicator. Calculated by dividing a 10-day exponential moving average of the number of advancing issues by the number of advancing plus declining issues, a "Breadth Thrust" occurs when the indicator rises from below 40% to above 61.5%. This indicates that the market has rapidly changed from an oversold condition to one of strength yet has not become overbought.

The Breadth Thrust Indicator was developed by Dr. Martin Zweig who points out that most bull markets begin with a Breadth Thrust. According to Zweig there have only been fourteen Breadth Thrusts in the S&P 500 since 1945 with an average gain of 24.6% following these Thrusts.