One API for Insider, Institutional & Congressional Trading Data

Four datasets, one account

Most insider-data providers cover one filing type. Form4API covers four, all reachable with the same X-Api-Key header and the same JSON response conventions:

• Form 4 — individual insider transactions, filed within 2 business days. See SEC Form 4 explained.
• Form 144 — an insider's notice of proposed sale, typically filed ahead of the matching Form 4. See Form 144 explained.
• 13F-HR — quarterly institutional holdings from managers with $100M+ AUM, CUSIP-to-ticker mapped. See 13F-HR filings explained.
• Congress (STOCK Act) — House Clerk periodic transaction reports, dollar ranges and disclosure lag included on every row. See the live congress feed.

Having all four in one place is the differentiator, not any single dataset on its own — pulling Form 4, Form 144, and 13F-HR yourself from EDGAR, and congressional PTRs from the House Clerk and Senate eFD systems, means reconciling four different formats, four different update cadences, and building your own joins across them. Two of those joins are already built: see below.

The convergence signal (Pro plan)

GET /v1/signals/convergence returns tickers where an insider cluster buy and a disclosed congressional purchase land within the same trailing window. It is a straightforward join across two of the four datasets — insider signals and congressional trades — not a black-box model: the response includes the qualifying insider count, the congressional legs with their amount ranges and disclosure lag, and a strength field that is documented arithmetic on those counts.

curl "https://api.form4api.com/v1/signals/convergence?ticker=NVDA" \
  -H "X-Api-Key: $FORM4API_KEY"

Not a trading signal — it detects and monitors overlapping disclosed activity, and a congressional PTR can be filed up to 45 days after the trade it reports, so a date in the response is a disclosure date, never a trade date. See insider vs congressional trading for the full honesty rules around this dataset, or browse the live convergence table on the congress page for the current count of qualifying tickers.

Free and Starter keys receive 402 PLAN_REQUIRED on this endpoint. It requires the Pro plan or higher — see the full endpoint reference.

The institutional-ownership overlay (Pro plan)

This is the second join, and it has nothing to do with Congress: inst_ownership_trend is a filter on GET /v1/transactions — the core Form 4 endpoint — that restricts results to companies whose 13F-HR institutional ownership is currently increasing, decreasing, or stable. Every Form 4 row you get back already carries that institutional-ownership context, computed from a separate quarterly filing type, joined per transaction at query time — you never run a second query against 13F-HR and stitch the two together yourself.

# Open-market insider buys where institutions are also accumulating
curl "https://api.form4api.com/v1/transactions?significant=true&code=P&inst_ownership_trend=increasing" \
  -H "X-Api-Key: $FORM4API_KEY"

This filter is a Pro-plan feature — it is not the same thing as access to the raw 13F-HR filing records, which sit on the Business plan (see the table below). Pro gets you the derived trend on Form 4 rows; Business gets you the underlying institutional holdings records themselves, plus Form 144.

Free and Starter keys requesting this parameter receive 403 PRO_TIER_REQUIRED. See the screener guide for the rest of the size and return filters this sits alongside.

What plan you need, feature by feature

Stated plainly and up front, so nothing here surprises you at a 402 or a 403. Every row below is a real gate enforced by the backend, not a marketing tier — see the pricing page for current plan details.

Response fields are visible on every tier once you have access to an endpoint — only the query-time filters and the higher-tier endpoints themselves are gated. The Free tier is 500 requests/day with full core-endpoint access and no credit card required, so you can evaluate the Form 4 and congress feeds before deciding whether the joined features are worth upgrading for.

Frequently asked questions