Momentum is a simple technical analysis indicator showing the difference between today’s closing price and the close N days ago. It is defined as a measure of velocity in a change in price. ”Momentum” in general refers to prices continuing to trend.

The momentum and indicator shows trend by remaining positive while an uptrend is sustained, or negative while a downtrend is sustained. A crossing up through zero may be used as a signal to buy, or a crossing down through zero as a signal to sell. How high (or how low when negative) the indicators get shows how strong the trend is.