FTB-C000356 / Indicator

Aroon Down

Aroon Down is a zero-to-100 score that rises as the rolling lowest low becomes more recent.

Also known asAroon low-recency line

Intermediate Formula defined 1 linked topicPublished

Definitions

In plain terms

A value of 100 means the selected lowest low occurs at the current endpoint under the declared tie rule.

Technical

The implementation must define window length, periods-since convention, low field, tie handling, and first-ready index.

Scope

It measures low recency, not the depth of the low or future downside.

Formula

Aroon Down = 100 * (n - periods since lowest low) / n
LaTeX: A^\downarrow_t=100\frac{n-k^L_t}{n}
SymbolMeaningUnit
nAroon periodperiods
k^L_tperiods since selected lowest lowperiods

Output unit: percent

Examples

  • A governed lesson calculates or identifies Aroon Down only after its parameters, state, timing, and edge cases are declared.

Common misconceptions

  • It measures low recency, not the depth of the low or future downside.

Concept relationships

Prerequisites

Related

Required by

Where this concept is used

Tutorials planned

These catalogued topics use this concept, but their complete build has not shipped yet.

  • D07-F02-A03 Important

Evidence and governance

  1. TA-Lib AROON Implementation TA-Lib · first party technical publication

    Supports: preferred label, short definition, technical definition, formula

    Limits: The pinned version supports reproducibility but does not make every platform's tie convention equivalent.

Reviewed by
fintech-builder-batch-007
Last reviewed
2026-07-27
Next review
2027-07-27
Record status
published
Written by

Fintech engineer building market-data and financial systems, and the author of every article, glossary record, and reference implementation on The Fintech Builder.