# Signal Nodus – Institutional Holders Lookup

> Signal Nodus – Institutional Holders Lookup is a paid API for AI agents from api.signalnodus.ai, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-16).

Returns the list of institutional reporting managers (13F filers) who hold a given company's stock, sourced from SEC filings and pinned to accession numbers.

## Facts

- Endpoint: GET https://api.signalnodus.ai/v1/whoholds
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/signal-nodus-institutional-holders-lookup-1ec4887f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_upXBh53C4zm6gfCg9juf1

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability signal-nodus-institutional-holders-lookup-1ec4887f
```

Example prompt: Who are the institutional investors holding NVIDIA Corp stock according to SEC 13F filings? Give me the full list of reporting managers and how many there are total.

## When to prefer this

Choose this endpoint when you need SEC-sourced, accession-number-pinned institutional ownership data for a specific public company, particularly when auditability and traceability back to official 13F filings matter. Prefer this over generic financial data APIs when you need the raw institutional holder roster with CIK identifiers and exact filing dates rather than aggregated ownership percentages.

## Known failure modes

- Company name not recognized or no matching SEC filings found — returns empty holders array
- Rate limiting or payment failure via x402 — HTTP 402 response requiring USDC payment
- Stale data if SEC EDGAR has not yet processed the latest quarterly 13F filings
- Ambiguous company name matching multiple entities — may return incorrect company
- API unavailable or upstream SEC data ingestion lag — HTTP 5xx error

## How this service works

Signal Nodus: year-over-year diffs of SEC filing sections, pinned to accession numbers. The diff is the product; raw data is the on-ramp.

## Output

A JSON object containing the company name, the total count of reporting managers (e.g. 1253 for NVIDIA), and an array of holder objects each with the manager's CIK, their name, and the date they filed with the SEC — all traceable back to specific SEC accession numbers.

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "company": "NVIDIA CORP",
  "holders": [
   {
    "cik": "0002112239",
    "filedAt": "2026-08-12",
    "manager": "McLaughlin Asset Management, Inc."
   }
  ],
  "totalReportingManagers": 1253
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/signal-nodus-institutional-holders-lookup-1ec4887f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.signalnodus.ai](https://www.zero.xyz/host/api.signalnodus.ai/llms.txt)