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Indicators/probuilder · probacktest · proorder · proscreener

VIminus

VIminus in ProBuilder returns the minus line of the Vortex Indicator, measuring downward trend movement over a chosen period. Syntax, formula, examples.

Syntax

probuilder
VIminus[period]

Parameters

NameTypeDefaultDescription
periodintegernoneNumber of bars used in the calculation. 14 is the common setting. Shorter periods react faster but cross more often.

The function takes no price argument, it works directly on the instrument's high, low and close series.

Formula

code
VM-  = ABS(low - high[1])          // downward vortex movement per bar
VI-  = Summation[period](VM-) / Summation[period](TR(close))

Each bar's downward vortex movement is the distance from the previous bar's high to the current bar's low. The VI- line is the sum of those distances over the period, normalised by the sum of true ranges over the same period. VIplus mirrors the construction using the distance from the previous low to the current high.

How it works

The Vortex Indicator treats the overlap between consecutive bars as directional information. A bar whose low sits far below the previous high represents strong downward continuation, and those distances accumulate in VI-. Dividing by the summed true range scales the result by overall volatility, so the line expresses what share of recent movement was downward rather than how large the movement was in absolute terms.

VI- and VI+ oscillate around 1 and are designed to be read together. The line on top identifies the dominant direction, and crossings between the two lines mark potential trend changes. Because both lines are ratios, readings are comparable across instruments and timeframes.

The indicator is a trend tool. In clearly directional markets the dominant line separates from the other and stays on top for extended stretches. In sideways markets the two lines braid around each other near 1 and crossings carry little information.

Examples

Example 1, Both vortex lines in one panel (Indicator)

probuilder
// Minus and plus lines of a 14-period Vortex Indicator
myVIminus = VIminus[14]
myVIplus = VIplus[14]
RETURN myVIminus AS "VI-", myVIplus AS "VI+"

Plots VI- and VI+ together, the standard presentation. The line currently on top indicates the dominant trend direction.

Example 2, Short entries on a bearish cross (ProOrder)

probuilder
// Sell short when downward movement takes over, cover on the reverse cross
vim = VIminus[14]
vip = VIplus[14]

IF vim CROSSES OVER vip THEN
  SELLSHORT 1 CONTRACT AT MARKET
ELSIF vim CROSSES UNDER vip THEN
  EXITSHORT AT MARKET
ENDIF

The strategy is short while VI- remains above VI+ and exits when the plus line regains the top, a symmetric trend-following rule on the vortex cross.

Example 3, Downtrend scan (ProScreener)

probuilder
vim = VIminus[14]
vip = VIplus[14]
SCREENER[vim > vip] ((vim - vip) AS "VI- spread")

Returns instruments where the minus line dominates, ranked by the spread between the two lines, the wider the spread, the more one-sided the recent downward movement.

Interpretation

ConfigurationReading
VI- above VI+Downward movement dominates, negative trend.
VI- below VI+Upward movement dominates, positive trend.
VI- crosses over VI+Bearish signal, downward pressure taking over.
VI- crosses under VI+Bullish signal, upward pressure resuming.

The spread between the lines gauges trend strength: a wide, persistent gap indicates a one-sided market, while lines clinging to each other near 1 indicate equilibrium. The indicator performs best in trending conditions and produces frequent false crossings in ranges, so it is often paired with a trend-strength filter such as ADX.

Common errors and gotchas

  • Passing a price argument. Unlike most indicator functions, the syntax is VIminus[14] with no parentheses. VIminus[14](close) is not the documented form.
  • Reading VI- in isolation. A rising VI- alone says little, the signal is relative to VIplus. Always compute and compare both lines.
  • Whipsaw in ranges. In sideways markets the lines cross repeatedly around 1. Crossing signals taken without a trend filter degrade quickly in consolidations.
  • Period sensitivity. Short periods such as 7 produce early but unreliable crosses, long periods such as 30 confirm trends late. Test the setting per market rather than assuming 14 fits everywhere.
  • VIplus, the opposite vortex line measuring upward movement.
  • DIminus, the negative directional line of the DMI system.
  • DIplus, the positive directional line of the DMI system.
  • DI, directional indicator spread.
  • ADX, trend strength measure often paired with directional lines.
  • ADXR, smoothed variant of ADX.
  • TR, the true range used as the normaliser in the vortex formula.
  • AverageTrueRange, smoothed true range.
  • SAR, parabolic stop and reverse, another trend-following tool.