# Normalized Price Transform

`D07-F08-A08` · Technical Indicators → Price Transforms · archetype `series-transform` · difficulty 2/5 · verification **verified**

Full page: https://docs.thefintechbuilder.com/technical-indicators/price-transforms/normalized-price-transform/
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 { normalizedPriceTransform } from "fintech-algorithms/technical-indicators/price-transforms/normalized-price-transform";
```

## Signature

```ts
normalizedPriceTransform(input)
```

Converts close into a rolling z-score against its own moving average and standard deviation.

## Parameters

| Name | Type | Required | Notes |
| --- | --- | --- | --- |
| `input` | `TopicInput` | yes | `bars` needs `timestamp` and `close`. From `parameters` this topic reads `period` (default 20, an integer of at least 2). |

## Returns

`TopicResult`

`series` holds `value`, the z-score, alongside the `mean` and `std` it was built from; `latest` carries the last element of each. `std` is the population standard deviation over the window, and a window whose `std` is 0 yields a null `value` while still reporting `mean` and `std`. The warm-up is the window.

## Warm-up

The first ``period` - 1 bars (19 with the default 20)` positions are `null`. `ready_at` is 19 on default parameters, set by `mean` and `std` becoming available on the same index as `value`.

## Errors

- When `period` is not an integer of at least 2 — throws Error
- When a `close` is not a finite number — 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
normalizedPriceTransform(input)
```

### Returns

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

```json
{
  "topic_id": "D07-F08-A08",
  "title": "Normalized Price Transform",
  "state": "calculated",
  "ready": true,
  "ready_at": 19,
  "series": {
    "value": [null, null, null, null, null, null],
    "mean": [null, null, null, null, null, null],
    "std": [null, null, null, null, null, null]
  },
  "latest": {
    "value": -1.9447777278294258,
    "mean": 104.20055051999998,
    "std": 2.164636086561151
  },
  "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/price-transforms/normalized-price-transform/
- Implementation source: https://github.com/IslamBaraka90/Fintech-Algorithms-Library/blob/main/src/technical-indicators/price-transforms/normalized-price-transform/impl.ts
- Package on npm: https://www.npmjs.com/package/fintech-algorithms
- Domain index for agents: https://docs.thefintechbuilder.com/technical-indicators/llms.txt