Form 3 — Initial Statement of Beneficial Ownership Dataset

Form 3 is the SEC filing that corporate insiders — officers, directors, and beneficial owners of more than 10% of any equity class — must submit when they first become subject to Section 16(a) of the Securities Exchange Act of 1934. This dataset contains structured records parsed from every Form 3 and Form 3/A filing on EDGAR since 2009. Each record captures one reporting person's initial beneficial ownership position in one issuer's securities, including non-derivative holdings, derivative instruments, relationship codes, and filing metadata — delivered as gzip-compressed JSON Lines files for direct programmatic consumption.

Dataset APIs

Dataset Files

What This Dataset Contains

Each record represents a single Form 3 filing (form type 3) or Form 3/A amendment (form type 3/A) as parsed from the SEC's EDGAR XML ownership-reporting format. The unit of observation is one reporting person–issuer pair: one insider's initial beneficial ownership position in one issuer's securities. A record contains the issuer's identity, the reporting owner's identity and relationship to the issuer, filing metadata, and two ownership tables — non-derivative holdings (Table I) and derivative holdings (Table II) — as they stood on the date the reporting person became an insider.

Form 3 is the Initial Statement of Beneficial Ownership of Securities, required under Section 16(a) and Rule 16a-3. The filing establishes a baseline ownership snapshot — not a transaction report — against which all subsequent changes on Forms 4 and 5 are measured. Many Form 3 filings report zero holdings in both tables, reflecting that the newly designated insider owned no securities of the issuer at the time of becoming an insider.

Since mid-2003, Form 3 filings have been submitted to EDGAR in XML conforming to the SEC's ownership-reporting schema. This dataset contains structured records parsed from those XML filings for submissions from 2009 onward.

The dataset is organized into monthly .jsonl.gz containers (e.g., 2025-06.jsonl.gz), with one JSON object per line representing a single Form 3 filing. A typical monthly container holds approximately 1,000 records (~180-280 KB compressed, ~1.5 MB decompressed). Each record is uniquely identified by an id field (32-character MD5 hash) and an accessionNo field (SEC accession number).

Content Structure of a Single Record

A record is organized into five content layers: issuer identification, reporting owner identification and relationship, filing metadata, the two ownership tables, and footnotes.

Issuer Identification (issuer object)

The issuer object identifies the company whose securities are disclosed:

• issuer.cik — the Central Index Key assigned by EDGAR, serving as a persistent numeric identifier for the issuer entity (e.g., "2054876").
• issuer.name — the issuer's legal or reporting name as submitted in the filing (e.g., "NMP Acquisition Corp.").
• issuer.tradingSymbol — the ticker symbol reported at filing time (e.g., "NMP"). May be absent for issuers without a listed equity class or when the filer omits it.

Reporting Owner Identification and Relationship (reportingOwner object)

The reportingOwner object identifies the person or entity filing Form 3. Fields include reportingOwner.cik and reportingOwner.name (for individuals, typically surname then given name; for entities such as trusts or funds, the entity name), plus an address sub-object with street1, street2, city, state, stateDescription (for non-U.S. addresses), and zipCode. The EDGAR XML schema allows multiple reporting owners on one filing for group filings, though this is rare in practice.

The owner's relationship to the issuer is encoded as four boolean flags plus one text field:

• isDirector — the owner is a member of the issuer's board of directors.
• isOfficer — the owner is an officer of the issuer as defined under Section 16.
• isTenPercentOwner — the owner beneficially owns more than 10% of a class of the issuer's equity securities.
• isOther — any other relationship triggering Section 16 obligations; when true, an accompanying otherText field may provide an explanation.
• officerTitle — free-text field present when isOfficer is true, specifying the officer's title (e.g., "Chief Financial Officer", "SVP & General Counsel"). Formatting and abbreviation conventions vary widely across filers.

Multiple flags may be true simultaneously (e.g., a person who is both a director and an officer).

Filing Metadata

• id — unique record identifier (32-character MD5 hash, e.g., "56c62418f60e4af1304a10495005cc59").
• accessionNo — the unique EDGAR filing identifier (e.g., "0001213900-25-059923"), linking the dataset record to the original filing on EDGAR. The accession number can be used to retrieve the source XML, the HTML rendering, and the EDGAR index page.
• filedAt — the date and time EDGAR accepted the filing, in ISO 8601 format with timezone (e.g., "2025-06-30T21:26:12-04:00").
• periodOfReport — the date as of which ownership is reported (e.g., "2025-06-30"). For an initial Form 3, this is typically the date the person became an insider. The period of report may predate the filing date, sometimes substantially, for late filings.
• dateOfOriginalSubmission — present only on Form 3/A amendments; records the filing date of the original Form 3 that the amendment supersedes.
• documentType — "3" for original filings, "3/A" for amendments.
• notSubjectToSection16 — boolean indicator that appears on some filings where the filer asserts that Section 16 obligations do not apply. Uncommon but present in the schema.
• schemaVersion — the SEC ownership XML schema version (e.g., "X0206").
• remarks — an optional free-text field where filers may include general comments about the filing. Infrequently populated.
• ownerSignatureName / ownerSignatureNameDate — signature line and date.

Non-Derivative Securities (Table I)

Table I reports holdings of non-derivative equity securities — typically common stock, preferred stock, or vested restricted stock units. Each row represents a distinct holding line:

• Title of security — free-text name of the security class (e.g., "Common Stock," "Class A Common Stock"). No controlled vocabulary; identical securities may appear under different names across filers.
• Amount of securities beneficially owned — the number of shares or units held as of the period of report. May be zero.
• Ownership form (D/I) — D for direct ownership or I for indirect ownership (held through another person or entity).
• Nature of indirect beneficial ownership — free-text field present when ownership is indirect, identifying the vehicle (e.g., "By Spouse," "By Revocable Trust," "By LLC").
• Footnote references — zero or more footnote IDs linking the row to explanatory footnotes.

A single reporting person may have multiple rows for the same security class when portions are held through different ownership vehicles. Table I is empty in a large share of Form 3 filings.

Derivative Securities (Table II)

Table II reports holdings of derivative securities convertible into, exercisable for, or deriving value from the issuer's equity securities. Common entries include stock options, warrants, convertible notes, unvested restricted stock units, and stock appreciation rights. Each row contains:

• Title of derivative security — free-text description (e.g., "Employee Stock Option (right to buy)," "Restricted Stock Units").
• Conversion or exercise price — the per-share price at which the derivative can be converted or exercised. Blank for instruments without a fixed exercise price (e.g., RSUs converting one-for-one).
• Date exercisable — the date on which the derivative becomes exercisable. May be blank if already exercisable or if exercisability is contingent on conditions described in footnotes.
• Expiration date — the date on which the derivative expires. Blank for instruments without a fixed expiration.
• Title of underlying security — the equity class into which the derivative converts, typically common stock.
• Amount or number of shares underlying — the number of shares obtainable upon full exercise or conversion.
• Ownership form (D/I) — same semantics as Table I.
• Nature of indirect beneficial ownership — same semantics as Table I.
• Footnote references — zero or more footnote IDs linking the row to explanatory footnotes.

Table II is frequently empty. When populated, it most commonly contains stock options or RSUs granted to incoming officers or directors.

Footnotes

Both tables may reference numbered footnotes stored as a separate block in the record. Footnotes provide information that does not fit the structured table fields: vesting schedules, performance conditions, shared voting or dispositive power arrangements, explanations of indirect ownership structures, or clarifications of security descriptions. Some table fields are only fully interpretable in conjunction with their associated footnotes.

Form 3 versus Form 3/A (Amendments)

A Form 3/A replaces the original Form 3 in its entirety — it is a full restatement, not a differential update. The amendment contains the complete ownership position as of the original period of report. The dataset distinguishes amendments via the form type field (3/A) and includes the date of original submission to link the amendment to the prior filing. An issuer-owner pair may have multiple records for the same insider-triggering event if amendments were filed; the most recent Form 3/A supersedes all prior versions.

Included and Excluded Content

Each record contains the fully parsed, structured data from the Form 3 XML filing: issuer identifiers, reporting owner identifiers and relationship codes, filing metadata, and the complete contents of both ownership tables with their footnotes. The data is delivered in JSONL format (gzip-compressed), enabling direct programmatic consumption without XML parsing.

The dataset does not include the raw XML or HTML source documents, which are retrievable from EDGAR via the accession number. It does not include EDGAR index-level metadata beyond what is described above (e.g., filing agent name or sub-day acceptance timestamp). It does not include any information from subsequent Form 4 or Form 5 filings — each record is an isolated snapshot of initial holdings, not a longitudinal ownership series.

Who Files Form 3 and When

Each record is a Form 3 or Form 3/A filed by a reporting person — an individual or entity that has newly become a corporate insider at a public company. The reporting person is the legal filer. The issuer is named in the filing but does not file the form, though in practice issuer compliance staff typically prepare and submit it under a power of attorney.

Reporting Persons

Section 16(a) of the Securities Exchange Act of 1934 defines three classes of insiders who must file:

Officers. Rule 16a-1(f) covers the issuer's president, principal financial officer, principal accounting officer or controller, any vice president in charge of a principal business unit, division, or function, and any other person who performs a policy-making function. The test is functional, not title-based.

Directors. All members of the issuer's board of directors or equivalent governing body, whether elected, appointed to fill a vacancy, or seated through a corporate transaction.

Ten-percent beneficial owners. Any person or entity that directly or indirectly holds more than 10% of any class of equity securities registered under Section 12. Beneficial ownership follows Rule 16a-1(a)(2), keyed to voting or investment power. Entities such as funds, trusts, and holding companies file in their own name.

Covered Issuers

The obligation applies only to issuers with equity securities registered under Section 12 of the Exchange Act — principally domestic companies listed on NYSE, Nasdaq, or another national securities exchange, plus companies registered under Section 12(g). Foreign private issuers are technically in scope, but Rule 3a12-3 exempts most from Section 16, so Form 3 filings by their insiders are rare. Registered investment companies with Section 12 securities are also covered.

Triggering Events

Form 3 is the initial statement of beneficial ownership — a snapshot of the reporting person's holdings at the moment insider status begins. Triggering events include:

• Election or appointment as a director — at an annual meeting, to fill a vacancy, or in connection with a merger or similar transaction.
• Assumption of an officer role — new hire, internal promotion, or reorganization that places a person in a Rule 16a-1(f) position.
• Crossing the 10% ownership threshold — the date beneficial ownership of any class of registered equity securities first exceeds 10%.
• IPO or initial Section 12 registration — when an issuer first registers equity securities under Section 12, all existing officers, directors, and 10%+ owners must file. The deadline here is the effective date of the registration statement, not the standard 10-day window.
• De-SPAC and similar business combinations — incoming officers and directors of the combined entity file upon assuming their roles, often producing clusters of filings at transaction close.

Deadline

Under Rule 16a-3(a), Form 3 is due within 10 calendar days of the triggering event. If the tenth day falls on a weekend or federal holiday, the deadline rolls to the next business day. The IPO exception is tighter: insiders at the time of initial Section 12 registration must file by the registration statement's effective date.

Form 3 is filed once per reporting person per issuer. There is no recurring or annual re-filing requirement. After the initial filing, ownership changes are reported on Form 4 (due within two business days of most transactions) or Form 5 (annual catch-up for exempt or previously unreported transactions).

How Form 3 Differs from Similar Filings and Datasets

Form 3 belongs to the Section 16(a) beneficial ownership reporting family alongside Forms 4 and 5. It also borders the Section 13(d) regime, Rule 144 notices, and proxy ownership tables.

Form 4 — Statement of Changes in Beneficial Ownership

Form 4 is the nearest neighbor. Both share the same XML schema, the same filer population, and the same Section 16(a) basis. Field structure overlaps heavily: reporting owner identity, issuer CIK, relationship checkboxes, and derivative/non-derivative securities tables appear in both.

The dividing line is triggering event. Form 3 captures the initial holdings snapshot at the moment a person becomes a Section 16 insider. It contains no transactions — only positions as of the trigger date. Form 4 reports every subsequent change: purchases, sales, exercises, gifts, and other dispositions. Form 4 records carry transaction codes, dates, prices, and pre/post-transaction share counts that Form 3 lacks entirely.

Volume differs by orders of magnitude. A typical insider files one Form 3 at the start and then dozens or hundreds of Form 4s over time. Form 3 establishes the baseline; Form 4 provides the activity stream.

Form 5 — Annual Statement of Changes in Beneficial Ownership

Form 5 completes the Section 16(a) trio. Same XML schema, same filer population. It is filed annually (within 45 days of fiscal year-end) to report transactions eligible for deferred reporting — small acquisitions, gifts, inheritance — or to correct missed Form 4 filings. Unlike Form 3, Form 5 contains transaction-level detail. It is periodic cleanup, not a one-time initial snapshot.

Schedule 13D and Schedule 13G

These filings operate under Section 13(d), a separate regime from Section 16(a). They trigger when any person or group crosses 5% beneficial ownership — a broader filer population and lower threshold than Form 3's 10%. The overlap is narrow: a 10%+ beneficial owner may owe both a Form 3 and a Schedule 13D/13G. But Schedule 13D requires narrative disclosure of the acquisition's purpose, funding sources, and plans for the issuer, while Form 3 contains none of this. Conversely, Form 3's structured derivative holdings tables have no equivalent in 13D/13G filings.

Form 144 — Notice of Proposed Sale of Securities

Form 144 is a forward-looking notice filed by affiliates and restricted-security holders who intend to sell under Rule 144. It discloses proposed share quantities and approximate sale dates — not current total holdings or derivative positions in the structured form that Form 3 provides. Form 144 signals intent to sell; Form 3 records the ownership baseline at insider-status onset.

Proxy Beneficial Ownership Tables (DEF 14A)

Proxy statements include ownership tables disclosing equity holdings of directors, named executive officers, and 5%+ shareholders. These resemble ownership snapshots but differ from Form 3 in authorship, granularity, and structure. Proxy tables are prepared by the issuer (not the individual insider), reflect a single company-chosen record date once per year, and aggregate multiple insiders into one HTML table. They lack the per-filer XML structure, derivative-instrument granularity, and relationship-type checkboxes of Form 3.

Form 3 is the only SEC filing that records both the moment a person becomes a Section 16 insider and their holdings at that moment, in a structured, individual-filer format. For longitudinal insider ownership analysis, Form 3 is the necessary starting point from which all subsequent Section 16 activity is measured.

Who Uses This Dataset

Form 3 filings record the initial ownership position of every new Section 16 insider. The dataset serves compliance, investment, governance, enforcement, research, and data-engineering workflows, each keyed to different fields in the record.

Section 16 Compliance Officers and Counsel

Corporate compliance teams and outside Section 16 counsel track whether newly appointed insiders file within the ten-day window. The primary check compares the period-of-report date against the filing date to flag late filers, which must be disclosed in the annual proxy under Item 405. Relationship-type codes help reconcile the insider roster against internal records. Amendment filings (Form 3/A) are tracked to catch corrections to holdings or ownership classification errors.

Equity Analysts and Portfolio Managers

A new Form 3 confirms an officer or director appointment, sometimes before press releases or proxy filings reflect the change. The reporting owner's identity, relationship to the issuer, and initial holdings — both equity positions and derivative securities like stock options — indicate management alignment and economic exposure. Tracking Form 3 filings across peer companies gives a running view of executive turnover and board refreshment.

Governance Researchers and Proxy Advisory Firms

Proxy advisors and governance teams use the isDirector and isOfficer flags to track board and management changes in near-real time. Issuer CIK, reporting-owner CIK, and relationship fields support director interlock databases and board-composition timelines. Ten-percent-owner filings surface new blockholders who may shift voting dynamics or signal activist interest.

SEC Enforcement and Examination Staff

Enforcement attorneys use the filing-date-to-period-of-report gap to investigate Section 16(a) compliance at scale. Patterns of late or missing filings across a company's insiders suggest weak compliance infrastructure. Cross-referencing Form 3 records against Form 4 transactions and Schedule 13D reports catches insiders who transact without ever filing an initial statement.

Academic Researchers

Finance and law scholars study initial insider ownership, governance structures, and regulatory compliance rates. The dataset supports cross-sectional analysis of holdings levels at appointment — equity exposure of new CEOs versus directors, option grants by firm size, compliance rates by regulatory regime.

Data Engineers and Quantitative Analysts

Data engineers use the Form 3 record as the baseline row in insider-ownership databases. Structured fields — issuer CIK, reporting-owner CIK, relationship flags, separate derivative and non-derivative holdings arrays — parse directly into relational or columnar stores. Quant teams treat the initial holdings snapshot as the starting position against which Form 4 transactions build a continuous ownership time series.

Use Cases

Flagging Late Section 16(a) Filers for Proxy Disclosure

Corporate compliance teams compare the period-of-report date against the filing date to identify Form 3 filings submitted beyond the ten-day statutory window. Late filers must be disclosed in the annual proxy under Item 405. Running this check programmatically across all insiders at a given issuer CIK produces a ready-made delinquent-filer list for proxy preparation and highlights repeat offenders or company-wide compliance gaps.

Detecting New Officer and Director Appointments

A new Form 3 filing confirms that a person has become a Section 16 insider at a specific issuer, often days or weeks before the appointment appears in press releases or proxy filings. Monitoring Form 3 submissions by issuer CIK and reading the relationship flags (isOfficer, isDirector, isTenPercentOwner) and the officerTitle field provides a near-real-time feed of executive hires, board additions, and new blockholders.

Establishing Baseline Holdings for Insider Ownership Time Series

Each Form 3 record captures the starting position — non-derivative shares and derivative instruments — from which all subsequent Form 4 and Form 5 transactions are measured. Data engineers use the Form 3 holdings tables as the initial row in per-insider ownership ledgers, keyed by reporting-owner CIK and issuer CIK. Without this baseline, cumulative position reconstruction from Form 4 transaction deltas is unreliable.

Mapping Initial Option and Equity Grants to Incoming Executives

Table II on a Form 3 filing often contains stock options, restricted stock units, or warrants granted to an incoming officer or director as part of a compensation package. Extracting exercise prices, expiration dates, and underlying share counts — supplemented by footnote text for vesting schedules — enables compensation analysts to benchmark initial grant sizes across peer companies, roles, and time periods.

Building Director Interlock and Board Composition Databases

Each Form 3 record links a reporting-owner CIK to an issuer CIK with explicit relationship flags. Aggregating these links across all issuers produces a point-in-time map of who sits on which boards and in what capacity. Governance researchers and proxy advisory firms use this to identify director interlocks, track individuals accumulating multiple directorships, and detect board overhauls.

Identifying New Ten-Percent Owners

Form 3 filings where the isTenPercentOwner flag is true signal that a person or entity has crossed the ten-percent beneficial ownership threshold. Unlike Schedule 13D/G filings, which trigger at 5% and focus on acquisition purpose and funding, the Form 3 record provides structured derivative and non-derivative holdings detail in a machine-readable format. Screening for these filings surfaces new blockholders who may affect corporate voting dynamics.

Access Dataset

Dataset Index JSON API

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          https://api.sec-api.io/datasets/form-3.json
        

This endpoint returns metadata about the dataset and a list of all available container files. No API key is required. The response includes the dataset name, description, last updated timestamp, earliest sample date, total records and total size, form types covered, container format, and an array of individual container files with download URLs, sizes, record counts, and update timestamps.

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          {
        

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            "datasetId": "1f11ba9b-dcc9-63c0-ab87-b225761576a5",
        

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            "datasetDownloadUrl": "https://api.sec-api.io/datasets/form-3.zip",
        

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            "name": "Form 3 - Initial Statement of Beneficial Ownership",
        

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            "updatedAt": "2026-03-28T05:00:03.000Z",
        

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            "earliestSampleDate": "2009-01-01",
        

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            "totalRecords": 731943,
        

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            "totalSize": 56939385,
        

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            "formTypes": ["3", "3/A"],
        

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            "containerFormat": "JSONL.GZ",
        

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            "fileTypes": ["JSONL"],
        

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            "containers": [
        

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              {
        

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                "downloadUrl": "https://api.sec-api.io/datasets/form-3/2026/2026-03.jsonl.gz",
        

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                "key": "2026/2026-03.jsonl.gz",
        

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                "size": 1384210,
        

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                "records": 4521,
        

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                "updatedAt": "2026-03-28T05:00:03.000Z"
        

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Download Entire Dataset

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          https://api.sec-api.io/datasets/form-3.zip?token=YOUR_API_KEY
        

Downloads a single archive containing all container files. An API key is required, passed as the ?token= query parameter or via the Authorization header.

Download Single Container

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          https://api.sec-api.io/datasets/form-3/2026/2026-03.jsonl.gz?token=YOUR_API_KEY
        

Downloads one individual container file. Each container is a .jsonl.gz file (gzipped JSON Lines) where every line represents one Form 3 filing record. An API key is required.

Frequently Asked Questions

What is the difference between Form 3 and Form 4? Form 3 is the initial statement of beneficial ownership filed when a person first becomes a Section 16 insider. It reports holdings — not transactions. Form 4 reports subsequent changes in ownership (purchases, sales, exercises, gifts) and includes transaction codes, dates, and prices that Form 3 does not contain. Both share the same XML schema and filer population.

Why do many Form 3 filings show zero holdings? A newly designated insider may not own any securities of the issuer at the time of becoming an insider. The regulatory requirement mandates filing even with zero holdings, establishing the baseline from which future changes are measured on Forms 4 and 5.

What does Form 3/A mean? Form 3/A is an amendment that replaces the original Form 3 in its entirety. It corrects errors such as wrong security descriptions, inaccurate share counts, or omitted holdings. The amendment contains the complete ownership position as of the original period of report, not just the corrected fields.

How can I tell if a Form 3 was filed late? Compare the period-of-report date (when the person became an insider) to the filing date (when EDGAR accepted the filing). If the gap exceeds 10 calendar days, the filing was late. Late Form 3 filings must be disclosed in the issuer's annual proxy statement.

Does the dataset include the original XML or HTML filing? No. The dataset contains structured records parsed from the EDGAR XML filings into JSONL format. The original XML and HTML source documents can be retrieved from EDGAR using the accession number included in each record.

How does Form 3 relate to Schedule 13D/13G? Form 3 is filed under Section 16(a) by officers, directors, and 10%+ owners. Schedule 13D/13G is filed under Section 13(d) by any person or group crossing 5% beneficial ownership. They use different beneficial-ownership calculations, different thresholds, and different content structures. A 10%+ owner may need to file both.

How far back does the dataset go? The dataset contains Form 3 filings from 2009 onward. EDGAR has accepted XML ownership filings since mid-2003, but the dataset's 2009 start date is a design choice.

What is the container file format? Each container file is a .jsonl.gz file — gzipped JSON Lines where each line is one complete Form 3 record as a JSON object. Container files are organized by time period.