# Volume Oscillator

`D07-F05-A14` · Technical Indicators → Volume Indicators · archetype `series-transform` · difficulty 2/5 · verification **verified**

Full page: https://docs.thefintechbuilder.com/technical-indicators/volume-indicators/volume-oscillator/
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 { volumeOscillator } from "fintech-algorithms/technical-indicators/volume-indicators/volume-oscillator";
```

## Signature

```ts
volumeOscillator(input)
```

Returns the difference between a fast and a slow simple moving average of raw volume.

## Parameters

| Name | Type | Required | Notes |
| --- | --- | --- | --- |
| `input` | `TopicInput` | yes | `bars` needs `timestamp` and `volume`. From `parameters` this topic reads `fast_period` (default 3) and `slow_period` (default 10, minimum `fast_period` + 1); `period` (default 14) is validated by the family but unused here. |

## Returns

`TopicResult`

`series` holds a single `value`, the fast volume SMA minus the slow one, in raw volume units rather than a percentage. `latest` carries its last element. The warm-up is set by the slow average.

## Warm-up

The first ``slow_period` - 1 bars (9 with the default 10)` positions are `null`. `ready_at` is 9 on default parameters.

## Errors

- When `slow_period` is not an integer greater than `fast_period` — throws Error
- When a bar carries a negative `volume` — throws Error
- When fewer than one bar is supplied — throws Error

## Complexity

Time `O(n)`, 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
volumeOscillator(input)
```

### Returns

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

```json
{
  "topic_id": "D07-F05-A14",
  "title": "Volume Oscillator",
  "state": "calculated",
  "ready": true,
  "ready_at": 9,
  "series": {
    "value": [null, null, null, null, null, null]
  },
  "latest": {
    "value": 6709.5
  },
  "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/volume-indicators/volume-oscillator/
- Implementation source: https://github.com/IslamBaraka90/Fintech-Algorithms-Library/blob/main/src/technical-indicators/volume-indicators/volume-oscillator/impl.ts
- Package on npm: https://www.npmjs.com/package/fintech-algorithms
- Domain index for agents: https://docs.thefintechbuilder.com/technical-indicators/llms.txt