13F holdings API comparison

The 13F holdings API for sourced ownership work

A practical comparison for teams building AI agents, screens, or ownership workflows on SEC 13F data. The core question is whether you need raw filings, broad market coverage, or a resolved point-in-time ownership spine.

Reviewed 2026-07-09

Decision rule

Pick the provider that can answer the exact query with the least hidden cleanup. For Arkolith, the proof point is not only that an endpoint returns data. It is that the row can be traced to a source filing, an accession, and the data model decision that produced it.

curl -H "Authorization: Bearer $ARKOLITH_KEY" \
  "https://arkolith.com/api/v1/funds/1067983/holdings"

Best for

  • Agent workflows that ask who owns a stock, what changed last quarter, and which filing proves it.
  • Resolved 13F holdings where CUSIP, ticker, filer, quarter, and accession need to stay attached.
  • Point-in-time research where the answer must reflect what was publicly known on a past date.
  • Content, dashboards, and internal tools that need a human-verifiable page for the same rows.

Not for

  • Real-time prices, intraday quotes, options chains, or crypto data.
  • Short positions, foreign holdings outside the 13F universe, or private assets not disclosed on 13F.
  • A full research terminal with analyst notes, charting, and portfolio management features.
  • Legal conclusions about whether a manager should have filed. The API models disclosed records.

Comparison table

This table compares provider shapes, not sales claims. Use it to decide what to test first.

Provider shapeBest forProofLimitations
Arkolith 13F APIResolved holdings, deltas, point-in-time reads, and MCP calls for AI agents.SEC accession, filing period, filer identity, resolved security fields, and provenance metadata.Deep on 13F ownership. It is not a broad price, fundamentals, or derivatives feed.
SEC EDGAR directPrimary-source filing access and legal source verification.Official SEC filings and accession numbers.You still build parsing, CUSIP resolution, amendment handling, deltas, caching, and agent tooling.
Broad market data APIsTeams that need one vendor for prices, fundamentals, estimates, and simple ownership fields.Vendor datasets and source links where documented.Often less explicit about field-level filing provenance, point-in-time semantics, and amendments.
Screeners and terminalsHuman analysts who want a UI, saved screens, charting, and exports.Terminal pages, exports, and linked filings where available.Usually less suited to metered MCP workflows and reproducible agent calls.

Source and provenance proof

Every holding row is tied to a SEC accession and filing period, not only to a vendor snapshot.

Amendment and supersession logic is modeled so corrected filings do not silently double count.

The same records power public stock and fund pages, which gives agents a link a human can inspect.

Run the path

FAQ

What is the best 13F API for AI agents?

Use the provider that keeps source proof attached to the row your agent reads. Arkolith is designed for that narrow job: resolved 13F holdings, point-in-time reads, and MCP or REST calls with filing provenance.

Does a 13F API show shorts?

No. SEC 13F filings primarily disclose long positions in reportable securities. A clean 13F API should make that limitation visible rather than imply that it captures the whole portfolio.

Why not call SEC EDGAR directly?

You should use EDGAR directly when the task is raw filing retrieval. Use a modeled API when you need parsing, amendment logic, identifier resolution, quarter deltas, and agent-ready calls.