An oscillator that measures the rate of price change (as opposed to the actual levels themselves). It is calculated by taking price differences for a fixed time interval. This positive or negative value is plotted around a zero line.
Momentum is used to detect trend weakness and likely reversal points. It is often underrated because of its simplicity. High Momentum readings (positive or negative) occur when a trend is at its strongest.
Momentum and rate of change (ROC) are simple technical analysis indicators showing the difference between today's closing price and the close N days ago. Momentum is the absolute difference in stock, whereas rate of change scales by the old close