Returns the Vortex minus line of the Vertex indicator.
- period= calculation period of the Vertex indicator
The Vortex indicator is composed of two lines that look at positive and negative trend movement separately. VI+ measures distance between a previous low and a subsequent high. VI- measures distance between a previous high and a subsequent low. Interpretation When VI+ is above VI- there is a positive trend. When VI- is above VI+ there is a negative trend.
The vortex indicator gives a bullish signal when VI+ is crosses over VI-. It gives a bearish signal when VI+ crosses under VI-.