The Vortex Indicator (VI) plots two oscillating lines that capture positive and negative price movement: VI+ (uptrend strength) and VI- (downtrend strength), derived from the relationship between highs, lows, and true range. Their interplay identifies the start and direction of a trend.

Reading the crossovers

The core signal is the crossover. When VI+ crosses above VI-, upward movement is overpowering downward — a potential uptrend beginning. When VI- crosses above VI+, the reverse — a potential downtrend. The separation between the lines reads trend strength: widely separated means a strong, clear trend; intertwined means chop and indecision.

How to use it

Use the Vortex as a trend-direction and onset filter, much like Aroon: a VI crossover with the lines separating signals a trend forming in that direction — a cue to trade with it. Intertwined lines say “no trend, don't trend-trade” (like ADX below 20). It's a directional complement to ADX's strength read.

VI+ over VI- says up is winning; VI- over VI+ says down is. When the lines are tangled, neither side is — and there's no trend to trade.

The limits

Like every crossover indicator, the Vortex lags and whipsaws in ranges — frequent, unreliable crossovers when the lines are intertwined. It's a context tool for reading trend direction and onset, not a standalone trigger. Confirm its crossovers with price structure and the regime, and ignore its signals when the lines are tangled — that tangle is the indicator honestly telling you it's a range.