# Volatility Stop

`D07-F06-A12` · Technical Indicators → Range and Volatility Indicators · archetype `series-transform` · difficulty 2/5 · verification **verified**

Full page: https://docs.thefintechbuilder.com/technical-indicators/range-and-volatility-indicators/volatility-stop/
Agent skill: `npx skills add IslamBaraka90/Fintech-Algorithms-Library` — https://docs.thefintechbuilder.com/guides/agent-skill/

## Install and import

```bash
npm install fintech-algorithms
```

```ts
import { volatilityStop } from "fintech-algorithms/technical-indicators/range-and-volatility-indicators/volatility-stop";
```

## Signature

```ts
volatilityStop(input)
```

Volatility Stop: a trailing long stop set `multiplier` ATRs below the highest close of the last `period` bars, and a short stop the same distance above the lowest close.

## Parameters

| Name | Type | Required | Notes |
| --- | --- | --- | --- |
| `input` | `TopicInput` | yes | `bars` is the required OHLCV array -- each bar carries `timestamp`, `open`, `high`, `low`, `close`, `volume` and an optional `basis`, strictly ordered by timestamp. From `parameters` this topic reads `period` (default 14, integer >= 2), used for both the rolling close extremes and the Wilder ATR, and `multiplier` (default 3, a finite number >= 0). |

## Returns

`TopicResult`

`series` holds `long_stop` and `short_stop`, both in price units; `latest` carries the last of each. They share a warm-up of `period - 1` leading nulls, so `ready_at` is 13 at the default period.

## Warm-up

The first ``period - 1` bars (13 at the default period)` positions are `null`. Both stops need the ATR seed and a full extremes window, and both complete at the same index. The stops do not ratchet or flip; each bar is recomputed from its own window.

## Errors

- When `parameters.period` is not an integer >= 2 — throws Error
- When `parameters.multiplier` is not a finite number, or is negative — throws Error
- When a bar is missing open, high, low, close, or volume, or one of them is not a finite number — throws Error

## Complexity

Time `O(n * period)`, space `O(n)`.

## Worked example

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

`input`:

```json
{
  "bars": [
    {
      "timestamp": "2024-01-02",
      "basis": "synthetic-unadjusted",
      "open": 100,
      "high": 101.45,
      "low": 98.695,
      "close": 100,
      "volume": 750000,
      "benchmark": 200
    },
    {
      "timestamp": "2024-01-03",
      "basis": "synthetic-unadjusted",
      "open": 101.49111452,
      "high": 103.38381693,
      "low": 100.05480022,
      "close": 101.78791214,
      "volume": 795117,
      "benchmark": 200.56326135
    },
    {
      "timestamp": "2024-01-04",
      "basis": "synthetic-unadjusted",
      "open": 102.45519048,
      "high": 104.6701838,
      "low": 100.91147007,
      "close": 102.9549389,
      "volume": 840234,
      "benchmark": 201.11020913
    }
  ],
  "parameters": {}
}
```

### Call

```ts
volatilityStop(input)
```

### Returns

object with 9 fields: topic_id, title, state, ready, ready_at, series, latest, parameters, …

```json
{
  "topic_id": "D07-F06-A12",
  "title": "Volatility Stop",
  "state": "calculated",
  "ready": true,
  "ready_at": 13,
  "series": {
    "long_stop": [null, null, null, null, null, null],
    "short_stop": [null, null, null, null, null, null]
  },
  "latest": {
    "long_stop": 98.43630241500071,
    "short_stop": 109.72647177499931
  },
  "parameters": {},
  "diagnostics": {
    "causal": true,
    "input_count": 96
  }
}
```

## Verification and provenance

Tier: **verified** (via E).

The worked example below is the figure published in this algorithm's article, replayed and asserted by the test suite on every build. The arithmetic cannot drift without the build failing.

Both tiers guarantee the signature. Full explanation: https://docs.thefintechbuilder.com/guides/verification/

Generated from the docs.json payload shipped inside fintech-algorithms@0.13.0.
The signature and parameter list are checked against the compiled implementation at build time,
so a description that contradicts the code fails the build rather than reaching this file.

## Links

- Article (how it works, step by step): https://thefintechbuilder.com/technical-indicators/range-and-volatility-indicators/volatility-stop/
- Implementation source: https://github.com/IslamBaraka90/Fintech-Algorithms-Library/blob/main/src/technical-indicators/range-and-volatility-indicators/volatility-stop/impl.ts
- Package on npm: https://www.npmjs.com/package/fintech-algorithms
- Domain index for agents: https://docs.thefintechbuilder.com/technical-indicators/llms.txt