Description: Momentum actually measures the velocity or speed of price as it progresses by subtracting price N periods ago from current price. If Momentum is above zero then price is trending higher else if Momentum is below zero price is trending lower (as measured over that period of time). If Momentum is turning, that just means the speed is slowing down, not that price is turning. Since price velocity will fall before price turns down, it can be used as a warning that the energy in the price move is falling in an up trend. In a down trend the reverse is true.
Usage: Direction change (smoothed version).