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13F Institutional Holdings by CUSIP
x402
13F Institutional Holdings by CUSIP is a paid API for AI agents from x402.professorsausages.com, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-28).
Returns every institutional holder of a given security (identified by CUSIP) for a quarter, sorted by position value, derived from SEC 13F filings
Price / call$0.02
Success—
StatusUnknown
How this service works
Every 13F institutional holder of one security (by CUSIP) for a quarter, sorted by position value — the inverted index EDGAR doesn't have
Output
A list of every institutional filer that reported holding the specified CUSIP in a given quarter, sorted descending by position value, including institution name, shares held, and reported value — essentially the inverted EDGAR index that maps one security to all its 13F holders.
Example use cases
Example prompt
“Which institutional investors hold the most of 037833100 (Apple) based on the latest 13F filings — show me all holders sorted by position value?”
Technical details
Endpoint
GEThttps://x402.professorsausages.com/13f-holdings/security/:cusip/holders?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need to look up all institutional holders of a specific security by CUSIP and want results sorted by position value — the inverted view that EDGAR's own interface does not provide natively. Ideal for equity research, ownership concentration analysis, or tracking which major funds entered or exited a position in a given quarter.
Side effects
- Invalid or unrecognized CUSIP returns empty results or 404
- CUSIP with no 13F filers in the requested quarter returns empty list
- Missing required CUSIP parameter returns 400 or validation error
- Payment not settled causes 402 response blocking data delivery
- Rate limiting or quota exceeded returns 429
- Stale data if quarter is not yet fully processed by SEC
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| chainrequired | string | Which chain the address belongs to. base and ethereum run full on-chain mode; the rest are list-only mode. |
| addressrequired | string | The address in that chain's native format (0x… for EVM, base58/bech32 otherwise). Checked against that chain's shape BEFORE the payment gate — a malformed address is a free 400, never a 402. |
Tags
x402
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