# 13-F Institutional Holdings > 13-F Institutional Holdings is a paid API for AI agents from agent.massive.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15). Retrieves SEC Form 13F quarterly filings showing institutional investment manager holdings for entities with $100M+ AUM ## Facts - Endpoint: GET https://agent.massive.com/stocks/filings/vX/13-F - Price: $0.01/call - Payment: x402 - Status: unknown - Last checked: 2026-09-15 - Activations on Zero: 0 - Tags: x402 - Canonical page: https://www.zero.xyz/c/13-f-institutional-holdings-7015dc10 - Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_h7-BzVwGD-DUi4By4-Ebe 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 13-f-institutional-holdings-7015dc10 ``` Example prompt: Pull up the most recent 13F filings from Berkshire Hathaway — their CIK is 0001067983 — and show me the last 10 sorted by filing date descending. ## When to prefer this Use this endpoint when you need structured SEC 13F quarterly holdings data for institutional investment managers, especially when filtering by specific filers via CIK or date ranges. Prefer this over general SEC EDGAR search when you need clean, queryable, agent-ready JSON rather than raw filing documents. Best for systematic tracking of institutional ownership disclosures, hedge fund monitoring, or compliance research. ## Known failure modes - Invalid or non-existent filer_cik returns empty results or error - Malformed date format (not YYYY-MM-DD) causes query rejection - Limit exceeding 1000 returns validation error - No filings matching the specified date range returns empty array - Payment failure (x402) blocks the request if USDC balance is insufficient ## How this service works SEC Form 13F filings data showing institutional investment manager holdings. Form 13F is required to be filed quarterly by institutional investment managers with at least $100 million in qualifying assets under management. Can't find what you're looking for? POST feedback to /feedback, no charge. ## Output A list of SEC Form 13F filing records for institutional investment managers, including filer CIK, filing date, and qualifying holdings data, paginated up to 1000 results per call and sortable by filing date. ## Request schema (JSON Schema) ```json { "type": "object", "$schema": "https://json-schema.org/draft/2020-12/schema", "required": [ "input" ], "properties": { "input": { "type": "object", "required": [ "type", "method" ], "properties": { "type": { "type": "string", "const": "http" }, "method": { "enum": [ "GET" ], "type": "string" }, "queryParams": { "type": "object", "properties": { "sort": { "type": "string", "default": "filing_date.desc", "description": "A comma separated list of sort columns. For each column, append '.asc' or '.desc' to specify the sort direction. The sort column defaults to 'filing_date' if not specified. The sort order defaults to 'desc' if not specified." }, "limit": { "type": "integer", "default": 100, "maximum": 1000, "minimum": 1, "description": "Limit the maximum number of results returned. Defaults to '100' if not specified. The maximum allowed limit is '1000'." }, "filer_cik": { "type": "string", "description": "SEC Central Index Key (10 digits, zero-padded) of the filing entity." }, "filing_date": { "type": "string", "description": "Date when the filing was submitted to the SEC (formatted as YYYY-MM-DD). Value must be formatted 'yyyy-mm-dd'." }, "filing_date.gt": { "type": "string", "description": "Filter greater than the value. Value must be formatted 'yyyy-mm-dd'." }, "filing_date.lt": { "type": "string", "description": "Filter less than the value. Value must be formatted 'yyyy-mm-dd'." }, "filing_date.gte": { "type": "string", "description": "Filter greater than or equal to the value. Value must be formatted 'yyyy-mm-dd'." }, "filing_date.lte": { "type": "string", "description": "Filter less than or equal to the value. Value must be formatted 'yyyy-mm-dd'." }, "filer_cik.any_of": { "type": "string", "description": "Filter equal to any of the values. Multiple values can be specified by using a comma separated list." } } } }, "additionalProperties": false }, "output": { "type": "object", "required": [ "type" ], "properties": { "type": { "type": "string" }, "example": { "type": "object" } } } } } ``` ## Response schema (JSON Schema) ```json { "type": "json", "example": { "status": "OK", "results": [ { "cusip": "023135106", "period": "2024-09-30", "put_call": null, "filer_cik": "0001067983", "form_type": "13F-HR", "filing_url": "https://www.sec.gov/Archives/edgar/data/1067983/0000950123-24-011775.txt", "file_number": "028-04545", "filing_date": "2024-11-14", "film_number": "241461756", "issuer_name": "AMAZON COM INC", "market_value": 1439212920, "other_managers": [ "Buffett Warren E" ], "title_of_class": "COM", "accession_number": "0000950123-24-011775", "investment_discretion": "DFND", "voting_authority_none": 0, "voting_authority_sole": 7724000, "voting_authority_shared": 0, "shares_or_principal_type": "SH", "shares_or_principal_amount": 7724000 }, { "cusip": "025816109", "period": "2024-09-30", "put_call": null, "filer_cik": "0001067983", "form_type": "13F-HR", "filing_url": "https://www.sec.gov/Archives/edgar/data/1067983/0000950123-24-011775.txt", "file_number": "028-04545", "filing_date": "2024-11-14", "film_number": "241461756", "issuer_name": "AMERICAN EXPRESS CO", "market_value": 311864270, "other_managers": [ "Buffett Warren E" ], "title_of_class": "COM", "accession_number": "0000950123-24-011775", "investment_discretion": "DFND", "voting_authority_none": 0, "voting_authority_sole": 1149942, "voting_authority_shared": 0, "shares_or_principal_type": "SH", "shares_or_principal_amount": 1149942 } ], "next_url": "https://api.massive.com/stocks/filings/vX/13-F?cursor=eyJsaW1pd...", "request_id": "a3f8b2c1d4e5f6g7" } } ``` ## More - Live health (JSON, refreshed every minute): https://www.zero.xyz/c/13-f-institutional-holdings-7015dc10/health.json - [Zero catalog index](https://www.zero.xyz/llms.txt) - [Other services from agent.massive.com](https://www.zero.xyz/host/agent.massive.com/llms.txt)