FTB-C000512 / Implementation concept

Rolling-Extreme Expiry

Rolling-Extreme Expiry is the row where the last owner of a channel boundary leaves the active window.

Also known asDonchian boundary expiry

Intermediate 1 linked topicPublished

Definitions

In plain terms

The boundary then steps to the next eligible maximum or minimum unless a new equal or more extreme value has entered.

Technical

Its timing follows finite n-row memory, current-row inclusion, and tied-owner handling rather than recursive decay.

Scope

Expiry is abrupt and contrasts with the geometric fading of EMA or ATR state.

Examples

  • A reviewer traces Rolling-Extreme Expiry from aligned inputs through its first-ready row and edge cases before accepting a displayed value.

Common misconceptions

  • Expiry is abrupt and contrasts with the geometric fading of EMA or ATR state.

Concept relationships

Prerequisites

Related

Contrasts with

Where this concept is used

Tutorials planned

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

  • D07-F04-A05 Important

Evidence and governance

  1. Donchian Channels TradingView · official platform documentation

    Supports: preferred label, short definition, technical definition

    Limits: Causal lagging, tie ownership, and exact breakout event rules are local implementation boundaries.

Reviewed by
fintech-builder-batch-009
Last reviewed
2026-07-30
Next review
2027-07-30
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.