Vortex Indicator (VI)
The Vortex Indicator (VI) is a trend-following technical indicator that uses two lines—VI+ (uptrend) and VI− (downtrend)—to identify trend direction, confirm existing trends, and signal potential reversals. VI+ and VI− are typically plotted below a price chart and colored (for example) green and red.
Origin
The indicator was introduced by Etienne Botes and Douglas Siepman in 2009.
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How it’s calculated
Calculation is performed over a chosen lookback period n (commonly 14–30 periods).
- True Range (TR) for the current period:
-
TR = max(
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- current high − current low,
- |current high − previous close|,
- |current low − previous close|
)
-
Vortex movements for the current period:
- VM+ = |current high − previous low|
-
VM− = |current low − previous high|
-
Sum the last n periods:
- SUM TRn = sum of TR over n periods
- SUM VMn+ = sum of VM+ over n periods
-
SUM VMn− = sum of VM− over n periods
-
Compute the indicator lines:
- VI+ = SUM VMn+ / SUM TRn
- VI− = SUM VMn− / SUM TRn
Repeat these steps each period to plot the VI+ and VI− lines.
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Typical settings and adjustments
- Default/lookback commonly used: 14 periods.
- To reduce whipsaws and false signals in choppy markets, increase n (for example, 25 periods).
- Shorter n makes the indicator more sensitive; longer n smooths it.
Interpretation and trading signals
- Bullish signal (trend reversal to uptrend): VI+ crosses above VI− and remains on top.
- Bearish signal (trend reversal to downtrend): VI− crosses above VI+ and remains on top.
- The line that is on top generally indicates the dominant trend direction.
Practical use and cautions
- Crossovers can generate false signals in sideways or noisy markets. Confirm with price action and other indicators (moving averages, RSI, volume, support/resistance).
- Typically used with a candlestick or price chart, with VI lines displayed beneath the price.
- Look for clear separation after a crossover and consider additional confirmation (price closing beyond a recent swing high/low, increased volume) before entering a trade.
- Adjust the period length to match the asset’s volatility and your timeframe.
Key takeaways
- The Vortex Indicator compares directional movement over a period to identify prevailing trend direction.
- VI+ above VI− indicates bullish dominance; VI− above VI+ indicates bearish dominance.
- Use longer lookback periods to reduce false signals and combine VI signals with other technical tools for confirmation.