3spread API reference

A REST API over SEC EDGAR filings: insider transactions, institutional holdings, beneficial ownership, fund portfolios, private offerings and more, parsed and standardized into one schema. Responses are JSON. Authentication is an API key, starting at 10,000 requests per day on the free Community tier.

Browse by dataset

• Insider transactions (Forms 3, 4, 5)
• Institutional holdings (Form 13F)
• Beneficial ownership (Schedule 13D / 13G)
• Private offerings (Form D)
• Proposed sales (Form 144)
• Fund portfolios (Form N-PORT)
• Fund census (Form N-CEN)
• Money market funds (Form N-MFP2)
• Proxy votes (Form N-PX)
• Reg A+ offerings (Forms 1-A / 1-K / 1-U / 1-Z)
• Registration statements (S-1, S-3, S-4, S-11, F-1, F-3)

Machine-readable

• OpenAPI specification (JSON)
• llms.txt, the full reference as markdown