FTB-C000407 / Formula component

RSI Relative Strength

RSI Relative Strength is Wilder average gain divided by Wilder average loss when the loss denominator is positive.

Also known asRS

Intermediate Formula defined 1 linked topicPublished

Definitions

In plain terms

It is the intermediate ratio transformed into the bounded RSI scale.

Technical

The implementation must branch explicitly for zero average loss and the both-zero flat state rather than relying on floating-point infinity.

Scope

It is internal gain-loss strength, not cross-sectional relative strength.

Formula

RS = Average Gain / Average Loss
LaTeX: RS_t=\frac{\bar{G}_t}{\bar{L}_t}
SymbolMeaningUnit
Average GainWilder average gainprice
Average LossWilder average loss magnitudeprice

Output unit: ratio

Examples

  • A governed lesson calculates or identifies RSI Relative Strength only after its inputs, window, state, scale, and edge cases are declared.

Common misconceptions

  • It is internal gain-loss strength, not cross-sectional relative strength.

Concept relationships

Prerequisites

Related

Where this concept is used

Evidence and governance

  1. Relative Strength Index TA-Lib · first party technical publication

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

    Limits: Seed, flat-series behavior, unstable periods, and platform compatibility must be frozen before claiming parity.

  2. New Concepts in Technical Trading Systems J. Welles Wilder Jr. · first party methodology

    Supports: historical attribution

    Limits: The bibliographic page alone is not an executable specification; equality, seeds, and state transitions require pinned rules.

Reviewed by
fintech-builder-batch-008
Last reviewed
2026-07-29
Next review
2027-07-29
Record status
published