ABS

Syntax

ABS(expression)

Parameters

Formula

ABS(x) = |x|

For any input, ABS returns a value that is zero or positive. A positive input passes through unchanged, a negative input has its sign flipped, and zero returns zero.

How it works

On every bar ABS evaluates its argument and strips the sign. It is a pure function with no lookback and no memory, so ABS(close - open) gives the size of the current bar's body regardless of whether the bar closed up or down. This makes it the standard tool for measuring distances, gaps and deviations where direction is not the point.

ABS pairs naturally with SGN, which returns the sign as -1, 0 or 1. Together they split a value into magnitude and direction: value = SGN(value) * ABS(value).

Examples

Example 1, Size of the current bar body (Indicator)

// Absolute distance between open and close, regardless of direction
bodySize = ABS(close - open)
RETURN bodySize AS "Body size"

The subtraction is negative on down bars and positive on up bars. Wrapping it in ABS returns the magnitude either way, so the plotted series is always zero or positive.

Example 2, Large single-bar moves (ProScreener)

// Instruments whose last bar moved more than 2% in either direction
pct = ABS(close - close[1]) / close[1] * 100
SCREENER[pct > 2](pct AS "Abs move %")

Using ABS makes the scan symmetric: a 2% drop and a 2% rise both qualify. Without it the condition would only catch moves in one direction.

Example 3, Distance-based stop guard (ProOrder)

// Block new entries when price sits far from its average
ma = Average[50](close)
gap = ABS(close - ma)
IF gap < close * 0.01 THEN
  IF NOT LongOnMarket AND close CROSSES OVER ma THEN
    BUY 1 CONTRACT AT MARKET
  ENDIF
ENDIF

ABS(close - ma) measures how far price has stretched from the moving average without caring which side it is on, so a single threshold covers both stretched-above and stretched-below cases.

Common errors and gotchas

• It only changes negatives. ABS never makes a value smaller in magnitude and never returns a negative. Applying it to an already positive series has no effect and can hide a sign you actually needed.
• Magnitude discards direction. After ABS you cannot tell whether the original value was up or down. Keep the raw value, or use SGN, if the sign matters later.
• Not a rounding function. ABS(-3.7) is 3.7, not 4. For rounding use ROUND, CEIL or FLOOR.

Related instructions

• SGN, returns the sign of a value as -1, 0 or 1, the direction that ABS discards.
• SQRT, square root, defined only for non-negative inputs that ABS can supply.
• SQUARE, squares a value, another way to remove sign at the cost of scale.
• MAX, larger of two values, useful with ABS to clamp distances.
• MIN, smaller of two values.
• ROUND, rounds to the nearest integer or decimal, unlike ABS.
• Momentum, raw price change that is often wrapped in ABS to measure size.
• Variation, percentage change between bars.