# Ticker-Change Chain Resolution

`D02-F03-A02` · Corporate Actions and Security Master Data → Identity Continuity · archetype `row-classify` · difficulty 3/5 · verification **verified**

Full page: https://docs.thefintechbuilder.com/corporate-actions-and-security-master-data/identity-continuity/ticker-change-chain-resolution/
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 { resolveTickerChain } from "fintech-algorithms/corporate-actions-and-security-master-data/identity-continuity/ticker-change-chain-resolution";
```

## Signature

```ts
resolveTickerChain(input)
```

Follows a symbol through renames in either direction. FB became META, and any store keyed on the symbol now holds two disconnected halves of one company's history.

## Parameters

| Name | Type | Required | Notes |
| --- | --- | --- | --- |
| `input` | `{ issuers: Issuer[]; instruments: Instrument[]; listings: Listing[]; assignments: Assignment[]; query: { symbol: string; asOf: string; queryAt: string } }` | yes | The four reference tables separate the layers a symbol actually sits on — issuer, instrument, listing, and the symbol assignment itself. Collapsing them is what makes rename handling ad hoc. |

## Returns

`{ status, direction, symbol, listingId, instrumentId, issuerId, chain, … }`

The resolved identifiers at every layer plus the chain traversed, so a surprising answer can be walked back.

## Errors

- When the query symbol or time is missing — throws

## Complexity

Time `O(assignments)`, space `O(chain)`.

## Worked example

This is the worked example published in the article, replayed by the test suite on every run. The output cannot drift.

### Input

`input`:

```json
{
  "issuers": [
    {
      "issuerId": "SYN-ISS-001"
    },
    {
      "issuerId": "SYN-ISS-002"
    }
  ],
  "instruments": [
    {
      "instrumentId": "SYN-INS-001",
      "issuerId": "SYN-ISS-001",
      "shareClassId": "SYN-CLS-A"
    },
    {
      "instrumentId": "SYN-INS-002",
      "issuerId": "SYN-ISS-002",
      "shareClassId": "SYN-CLS-COM"
    }
  ],
  "listings": [
    {
      "listingId": "SYN-LST-001",
      "instrumentId": "SYN-INS-001",
      "venueMic": "XNAS",
      "currency": "USD"
    },
    {
      "listingId": "SYN-LST-002",
      "instrumentId": "SYN-INS-001",
      "venueMic": "XLON",
      "currency": "GBP"
    },
    {
      "listingId": "SYN-LST-099",
      "instrumentId": "SYN-INS-002",
      "venueMic": "XNAS",
      "currency": "USD"
    }
  ],
  "assignments": [
    {
      "assignmentId": "SYN-ASG-100",
      "revision": 1,
      "status": "active",
      "listingId": "SYN-LST-001",
      "symbol": "ALP",
      "effectiveAt": "2020-01-02T14:30:00Z",
      "validTo": "2024-06-10T13:30:00Z",
      "announcedAt": "2019-12-18T15:00:00Z",
      "availableAt": "2019-12-18T15:05:00Z",
      "changeKind": "initial_listing",
      "sourceId": "SYN-SRC-XNAS-100"
    },
    {
      "assignmentId": "SYN-ASG-200",
      "revision": 1,
      "status": "active",
      "listingId": "SYN-LST-001",
      "symbol": "NXT",
      "effectiveAt": "2024-06-10T13:30:00Z",
      "validTo": "2025-01-10T14:30:00Z",
      "announcedAt": "2024-05-15T12:00:00Z",
      "availableAt": "2024-05-15T12:07:00Z",
      "changeKind": "administrative",
      "sourceId": "SYN-SRC-XNAS-200-R1"
    },
    {
      "assignmentId": "SYN-ASG-200",
      "revision": 2,
      "status": "active",
      "listingId": "SYN-LST-001",
      "symbol": "NXT",
      "effectiveAt": "2024-06-10T13:30:00Z",
      "validTo": "2025-01-15T14:30:00Z",
      "announcedAt": "2024-05-15T12:00:00Z",
      "availableAt": "2024-12-20T16:10:00Z",
      "changeKind": "administrative",
      "sourceId": "SYN-SRC-XNAS-200-R2"
    }
  ],
  "query": {
    "direction": "listing_to_symbol",
    "listingId": "SYN-LST-001",
    "queryAt": "2024-07-01T15:00:00Z",
    "asOf": "2024-08-01T12:00:00Z"
  }
}
```

### Call

```ts
resolveTickerChain(input)
```

### Returns

object with 21 fields: status, direction, queryAt, asOf, symbol, listingId, instrumentId, issuerId, …

```json
{
  "status": "resolved",
  "direction": "listing_to_symbol",
  "queryAt": "2024-07-01T15:00:00Z",
  "asOf": "2024-08-01T12:00:00Z",
  "symbol": "NXT",
  "listingId": "SYN-LST-001",
  "instrumentId": "SYN-INS-001",
  "issuerId": "SYN-ISS-001",
  "shareClassId": "SYN-CLS-A",
  "venueMic": "XNAS",
  "currency": "USD",
  "assignmentId": "SYN-ASG-200",
  "revision": 1,
  "changeKind": "administrative"
}
```

Showing 14 of 21 fields.

## Verification and provenance

Tier: **verified** (via input-expected).

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@0.13.1.
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/corporate-actions-and-security-master-data/identity-continuity/ticker-change-chain-resolution/
- Implementation source: https://github.com/IslamBaraka90/Fintech-Algorithms-Library/blob/main/src/corporate-actions-and-security-master-data/identity-continuity/ticker-change-chain-resolution/impl.ts
- Standalone repository: https://github.com/IslamBaraka90/Fintech-Ticker-Change-Chain-Resolution-Corporate-Actions-algorithm
- Package on npm: https://www.npmjs.com/package/fintech-algorithms
- Domain index for agents: https://docs.thefintechbuilder.com/corporate-actions-and-security-master-data/llms.txt