SAREXT

Summary

Extended Parabolic SAR (stop and reverse) giving the caller full control over the initial state and separate acceleration factors for long and short positions. Unlike SAR, it returns negative values while short so reversals are distinguishable. Sign flip of the output marks a trend reversal (positive=long stop, negative=short stop).

Formula

SAR_next = SAR + AF*(EP - SAR), then clamped within the prior and current bar's range. On penetration, reverse: set SAR=EP (clamped), reset AF to its Init value, EP=extreme of the new direction. Output is +SAR when long, -SAR when short. On reversal an optional offset is applied: long->short SAR*(1+offset), short->long SAR*(1-offset).

Inputs

inHigh — High price of each bar
inLow — Low price of each bar

Outputs

outReal — SAR stop level; positive while long, negative while short

Parameters

Parameter	Type	Default	Accepted values	Description
`optInStartValue`	real	0	any real	Initial SAR/direction: 0 auto, >0 start long at value, <0 start short at \|value\|
`optInOffsetOnReverse`	real	0	≥ 0	Fractional offset applied to the stop on each reversal
`optInAccelerationInitLong`	real	0.02	≥ 0	Initial acceleration factor when long
`optInAccelerationLong`	real	0.02	≥ 0	AF increment per new long extreme
`optInAccelerationMaxLong`	real	0.2	≥ 0	Cap on the long acceleration factor
`optInAccelerationInitShort`	real	0.02	≥ 0	Initial acceleration factor when short
`optInAccelerationShort`	real	0.02	≥ 0	AF increment per new short extreme
`optInAccelerationMaxShort`	real	0.2	≥ 0	Cap on the short acceleration factor

Properties

Numerical Stability: Path-Dependent

Display Flags
✅ Overlap Input i
☐ Independent Y-Axis
☐ Candlestick

Implementation

TA-Lib Definition: sarext.c · sarext.yaml

Native	File
C	`ta_SAREXT.c`
Rust	`sarext.rs`
Java	`Core_SAREXT.java`

TA-Lib is also available for Python, R and more using a wrapper.

Aliases

Parabolic SAR Extended, Extended Parabolic Stop and Reverse