Zweig Breadth Thrust

Install and import#

npm install fintech-algorithms

import { calculate } from "fintech-algorithms/market-breadth-and-internals/thrust-and-pressure/zweig-breadth-thrust";

Signature#

calculate(rows, emaLength, lowThreshold, highThreshold, maxSessions)

Detects the rare initiation signal: the advance ratio moving from below a low threshold to above a high one inside a bounded number of sessions. It fires a handful of times in a generation, which is the point — and also why it cannot be validated on a short sample.

Parameters#

Returns#

{ status, trigger_date, ema, sessions, series }

The trigger date if one occurred, with the EMA path and session count so a near-miss can be seen rather than merely absent.

Errors#

• When lowThreshold ≥ highThreshold — throws

Complexity: time O(n), space O(n).

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#

[
  {
    "session_date": "2026-01-05",
    "advances": 520,
    "declines": 480,
    "ready": true
  },
  {
    "session_date": "2026-01-06",
    "advances": 500,
    "declines": 500,
    "ready": true
  },
  {
    "session_date": "2026-01-07",
    "advances": 480,
    "declines": 520,
    "ready": true
  }
]

Showing 3 of 24 elements.

10

0.4

0.615

10

Call#

calculate(rows, emaLength, lowThreshold, highThreshold, maxSessions)

Returns#

object with 5 fields: status, trigger_date, ema, sessions, series

{
  "status": "thrust",
  "trigger_date": "2026-01-28",
  "ema": 0.6648021169863199,
  "sessions": 6,
  "series": [
    {
      "date": "2026-01-05",
      "ratio": 0.52,
      "ema": 0.52,
      "state": "idle"
    },
    {
      "date": "2026-01-06",
      "ratio": 0.5,
      "ema": 0.5163636363636364,
      "state": "idle"
    },
    {
      "date": "2026-01-07",
      "ratio": 0.48,
      "ema": 0.5097520661157025,
      "state": "idle"
    }
  ]
}

Diagrams#

Calculation flow#

flowchart LR
    A["Ordered A and D counts"] --> B["Breadth ratio A/(A+D)"]
    B --> C["Update EMA10"]
    C --> D{"EMA < 0.400?"}
    D -->|"Yes"| E["Arm or refresh clock"]
    D -->|"No"| F{"Armed and EMA > 0.615?"}
    E --> G["Advance session age"]
    G --> F
    F -->|"Yes, age ≤ 10"| H["Publish thrust now"]
    F -->|"No, age > 10"| I["Expire"]
    F -->|"No, age ≤ 10"| G

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
• Advance-Decline Indicators — StockCharts ChartSchool
• Advance Decline Ratio Indicators, Chapter 5 — Greg Morris, StockCharts
• Historical-example decision

The rest of the Thrust and Pressure family#

• Arms Index (TRIN)TRIN: the advance/decline issue ratio divided by the advance/decline volume ratio.
• Advance/Decline Volume LineThe cumulative line built from advancing minus declining volume rather than issue counts.
• Upside/Downside Volume RatioAdvancing volume over declining volume for one session.
• Cumulative TICKAccumulates the net count of issues trading on an uptick versus a downtick.
• Breadth-Divergence DetectorFlags sessions where the index and a breadth measure move meaningfully in opposite directions — the classic warning that an adv…