U.S. Securities and Exchange Commission
US >5% beneficial-ownership filings - structured XML (post-2024-12-18) with exact percent-of-class; both issuer and holder keyed on the SEC CIK
Source
Feed (what to expect)
EDGAR full-text-search API (efts.sec.gov) for [issuer,filer] CIK pairs + per-filing primary_doc.xml from sec.gov/Archives.
Quirks
The top free ownership lane in the corpus: US held 19,192 percentage-less edges + 171,620 facilities and only 3 US percentages before this.
Reconciliation
Schema
Feeds (axes)
Record kinds
Identifier schemes