> ## Documentation Index
> Fetch the complete documentation index at: https://docs.secapi.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# 13F API — Institutional Holdings Data for Investors and AI Agents

> Use SEC API to query structured Form 13F holdings, compare manager filings, monitor institutional ownership changes, and preserve source evidence for investor agents.

Use this page when you need Form 13F holdings in a product, screen, monitor, or AI agent. SEC API parses institutional manager filings and exposes structured holdings data through REST, SDKs, CLI, and hosted MCP while preserving the filing evidence you need to audit the result.

<CardGroup cols={3}>
  <Card title="Evaluate this workflow" icon="clipboard-check" href="/evaluate/13f-api">
    Test manager holdings, quarter comparisons, identifiers, and source trails.
  </Card>

  <Card title="13F monitor workflow" icon="workflow" href="https://secapi.ai/workflows/13f-monitor-agent">
    See the buyer-facing agent workflow.
  </Card>

  <Card title="Get an API key" icon="key-round" href="https://secapi.ai/signup?utm_source=docs&utm_medium=13f_api&utm_campaign=docs_to_signup">
    Create an account and run the first holdings request.
  </Card>
</CardGroup>

## What to verify first

* **Manager identity**: Confirm manager CIK, manager name, report period, filed date, and accession number.
* **Issuer identity**: Verify CUSIP, issuer name, ticker, and any issuer CIK mapping your workflow depends on.
* **Change semantics**: Decide how you will treat added, removed, increased, reduced, and unchanged positions across quarters.
* **Timing**: 13F filings are quarterly and delayed. They are useful for ownership history and manager behavior, not real-time position proof.
* **Agent contract**: Require the final answer to preserve source URL, request ID, filing date, report period, and caveats.

## Quick start

Get Berkshire Hathaway's current 13F holdings:

```bash theme={null}
curl -H "x-api-key: $SECAPI_API_KEY" \
  "https://api.secapi.ai/v1/owners/13f?cik=0001067983&limit=10"
```

```json theme={null}
{
  "data": [
    {
      "issuer_name": "APPLE INC",
      "cusip": "037833100",
      "value": 84248000,
      "shares": 400000000,
      "share_type": "SH",
      "investment_discretion": "SOLE",
      "voting_authority_sole": 400000000
    }
  ],
  "period": "2024-Q4",
  "manager_name": "BERKSHIRE HATHAWAY INC",
  "filed_at": "2025-02-14"
}
```

Compare holdings across quarters:

```bash theme={null}
curl -H "x-api-key: $SECAPI_API_KEY" \
  "https://api.secapi.ai/v1/owners/13f/compare?cik=0001067983&period_a=2024-Q3&period_b=2024-Q4"
```

## Give this prompt to your agent

<Prompt>
  Evaluate SEC API for a 13F manager-monitor workflow. Pull the latest reported holdings for Berkshire Hathaway, compare the two latest available quarters if the endpoint supports it, and return added, removed, increased, and reduced positions. Preserve manager CIK, issuer identifiers, report period, filed date, accession number, source URL, requestId, and a caveat that 13F data is quarterly and delayed.
</Prompt>

## Use cases

### Track position changes for top managers

Monitor when the largest hedge funds and asset managers add or exit positions. The compare endpoint surfaces exactly what changed.

### Build a 13F-based stock screener

Screen for stocks that are being accumulated by multiple institutional investors simultaneously. Cross-reference with insider buying for stronger conviction signals.

### Backtest institutional following

Analyze whether stocks with increasing institutional ownership outperform. Use historical 13F data to build and validate strategies.

### Give 13F data to an agent

Use 13F endpoints when your agent needs to answer questions like "which managers increased NVDA exposure last quarter?" or "which new positions appeared across multiple high-conviction funds?" Keep the manager CIK, reporting period, accession number, and request ID attached to the answer so the result can be audited.

### Compliance and reporting

Wealth managers and fund administrators can use 13F data to verify holdings disclosures and track competitive positioning.

## When SEC API is the right layer

Raw EDGAR is still the source of record. SEC API is the right layer when you want a normalized contract for managers, holdings, identifiers, source links, and agent-readable responses without maintaining your own 13F parser and quarter-comparison code.

<CardGroup cols={3}>
  <Card title="13F monitor workflow" icon="workflow" href="https://secapi.ai/workflows/13f-monitor-agent">
    See how the ownership data becomes a recurring investor-agent workflow.
  </Card>

  <Card title="Ownership API page" icon="users" href="https://secapi.ai/apis/ownership">
    Review the broader ownership surface: 13F, insiders, holders, and governance.
  </Card>

  <Card title="Pricing and limits" icon="credit-card" href="/evaluate/pricing-and-limits">
    Check the meter and fanout posture before monitoring many managers.
  </Card>
</CardGroup>

## API endpoints

| Endpoint                     | Description                           |
| ---------------------------- | ------------------------------------- |
| `GET /v1/owners/13f`         | List holdings for a 13F filer         |
| `GET /v1/owners/13f/compare` | Compare holdings between two quarters |

## Get started

<Card title="Get your API key" icon="key" href="https://secapi.ai/signup?utm_source=docs&utm_medium=13f_api_bottom&utm_campaign=docs_to_signup">
  Start pulling 13F data with source trails and request metadata.
</Card>

* [Monitor 13F Holdings Tutorial](/tutorials/monitor-13f-holdings)
* [Ownership Workflows](/ownership-workflows)
* [API Reference](/api-reference/owners)