fintech-algorithms

Arms Index (TRIN)

Install and import

bash
npm install fintech-algorithms
ts
import { calculate } from "fintech-algorithms/market-breadth-and-internals/thrust-and-pressure/arms-index-trin";

Signature

calculate(row)

Worked example

executed Captured by running this function on the input its own test provides. Real output of real code — but not asserted against a published figure.

Input

row
{
  "session_date": "2026-02-05",
  "advances": 600,
  "declines": 400,
  "unchanged": 20,
  "advancing_volume": 120000000,
  "declining_volume": 60000000,
  "ready": true
}

Call

calculate(row)

Returns

object with 4 fields: status, value, issue_ratio, volume_ratio

{
  "status": "resolved",
  "value": 0.75,
  "issue_ratio": 1.5,
  "volume_ratio": 2
}

Diagrams

Arms Index (TRIN) — decision boundary
Arms Index (TRIN) — family map

How it works

This page states the contract — how to call it correctly. The article explains the concept: why it works, and where it breaks.

Read the article →

References

  • Claim-to-source map
  • Arms Index (TRIN) — Fidelity
  • Arms Index (TRIN) — StockCharts ChartSchool
  • ArmsIndex Function — TradeStation
  • Historical-example decision