Form 10-C Files Dataset

The Form 10-C Files Dataset is a complete EDGAR-era archive of Form 10-C and Form 10-C/A submissions — the short, single-purpose notice that Nasdaq-quoted issuers filed when their outstanding share count of the quoted class moved by five percent or more, or when the issuer changed its legal name. One record corresponds to a single accession (a Form 10-C or 10-C/A as accepted by EDGAR), packaged as a parsed metadata.json plus one or more plain-text document-N.txt files. The corpus spans the full active life of Form 10-C in EDGAR, from January 1994 through the form's discontinuation in August 1997, and is distributed as ZIP containers partitioned by year and month in the form YYYY/YYYY-MM.zip. Because Form 10-C was created and retired within a single, short, ASCII-only filing era, the underlying template is essentially constant across every record in the dataset.

Dataset APIs

Dataset Files

Who Filed Form 10-C and What Triggered It

Filer population

Form 10-C was filed by the issuer itself, and only by issuers with a class of equity securities quoted on the Nasdaq interdealer quotation system (including the Nasdaq National Market and Nasdaq SmallCap Market). The filer was an Exchange Act reporting company under Section 13 of the Securities Exchange Act of 1934 (by virtue of a class registered under Section 12) or under Section 15(d) (by virtue of an effective Securities Act registration statement that triggered ongoing reporting).

Issuers listed on a national securities exchange (NYSE, AMEX), traded only on the pink sheets, or not publicly quoted at all were outside the Form 10-C population. Foreign private issuers reporting on the Form 20-F regime were likewise not within scope. Transfer agents, market makers, Nasdaq, and shareholders never filed the form, even though the underlying share-count or name-change information often originated from their records or actions.

Triggering events

A Form 10-C filing was required upon either of two events affecting the Nasdaq-quoted class:

1. A cumulative change of 5 percent or more in the number of shares of that class outstanding, measured against the most recently reported share count. Because the test was cumulative rather than per-transaction, a series of smaller events within a quarter (splits, reverse splits, stock dividends, repurchases, conversions or exercises of convertible securities, warrants, or options, secondary offerings, private placements, M&A issuances, employee plan issuances) could aggregate to cross the threshold.
2. A change in the issuer's name.

Either event independently triggered the filing; both could be reported on a single Form 10-C when they coincided. The trigger applied only to the affected Nasdaq-quoted class, not to every class of equity the issuer might have outstanding.

Regulatory framework

Form 10-C was prescribed under Sections 13 and 15(d) of the Exchange Act, implemented through Rule 13a-17 (for Section 13 reporters) and Rule 15d-17 (for Section 15(d) reporters). These parallel rules required Nasdaq-quoted issuers to report qualifying share-count changes and name changes on Form 10-C. The form sat alongside, not in place of, the issuer's Forms 10-K, 10-Q, and 8-K obligations.

Timing and deadlines

Form 10-C was due within 10 days after the close of the calendar quarter in which the triggering event occurred. Multiple qualifying events within the same quarter could be consolidated on a single filing covering that quarter.

Amendments: Form 10-C/A

Form 10-C/A filings are amendments to a previously filed Form 10-C, used to correct misstated share counts, revise the description of the underlying transaction, or otherwise restate or supplement the original. Amendments share the same filer population and regulatory basis as the original form; they are corrections, not separately triggered disclosures.

Discontinuation in August 1997

The SEC eliminated Form 10-C in August 1997. Its content had become duplicative: outstanding-share counts for each class of common equity were already reported on the cover pages of Forms 10-Q and 10-K, and issuer name changes had become reportable as a current event on Form 8-K. Removing Form 10-C eliminated the parallel Nasdaq-specific channel without reducing the information available to investors.

Important distinctions

• The trigger is tied to the Nasdaq-quoted class. Issuers with multiple classes filed only in respect of the affected, Nasdaq-quoted class.
• Exchange-listed issuers (NYSE, AMEX) did not use Form 10-C; their share-count and name-change information flowed through regular Exchange Act reports and exchange-level notifications.
• The legal filer is the issuer. Selling shareholders, underwriters, and transfer agents involved in the underlying corporate action are not filers.
• The dataset covers EDGAR submissions from January 1994 through the form's discontinuation in August 1997. Pre-EDGAR paper filings of Form 10-C are not included.

Anatomy of a Form 10-C Record

What one record represents

One record is a single Form 10-C or Form 10-C/A submission to EDGAR, addressed by its SEC accession number. The unit is the entire filing as accepted: the parsed EDGAR submission header serialised as metadata.json, plus every textual document EDGAR distributed under that accession, written to disk as one or more document-N.txt files. Image attachments from the original submission are excluded by design. Everything else that the issuer filed in textual form is preserved verbatim.

Container and per-record layout

The dataset is distributed as ZIP archives partitioned by year and month, in the form YYYY/YYYY-MM.zip. Each month-level archive expands to a folder YYYY-MM/ holding one sub-folder per accession. Accession folders are named with the 18-digit numeric form of the accession (no dashes — e.g. 000093211197000015 for accession 0000932111-97-000015). Each accession folder contains exactly one metadata.json plus one or more document-N.txt files. The N in document-N.txt is the EDGAR document sequence number; original EDGAR filenames are not preserved on disk, but the original sequence, type, size, URL, and description are retained inside metadata.json under documentFormatFiles[], which serves as the join key back to EDGAR identities. Most accessions contain a single document-1.txt because 10-C filings of this era were almost always single-document submissions; the layout admits multi-document filings, and when present they are stored in EDGAR sequence order.

metadata.json fields

The metadata file follows the standard SEC-API submission schema and captures the EDGAR submission header in structured JSON. The principal fields are:

• formType: either "10-C" or "10-C/A".
• accessionNo: canonical dashed SEC accession number, e.g. "0000932111-97-000015".
• filedAt: ISO-8601 timestamp with EDGAR's eastern-time offset, recording when the submission was accepted.
• periodOfReport: the effective date of the share-count change or name change being reported.
• description: the static SEC-supplied label "Form 10-C - Change of number of shares outstanding or change of issuer name".
• linkToTxt: URL of the full SGML submission text file on EDGAR (the original wrapper containing all <DOCUMENT> blocks).
• linkToHtml: URL of the EDGAR filing index page.
• linkToFilingDetails: URL of the EDGAR archive folder for the filer.
• linkToXbrl: empty string for every record (Form 10-C predates structured-data filing).
• dataFiles: empty array, for the same reason.
• seriesAndClassesContractsInformation: empty array (the field is fund-specific and does not apply to 10-C filers).
• id: an internal hex record identifier.
• documentFormatFiles[]: an ordered list, one entry per EDGAR-listed document, each carrying sequence, size, documentUrl, type, and an optional description. A trailing entry with blank sequence and type, and description: "Complete submission text file", points to the full SGML submission wrapper by URL; this wrapper is referenced but not stored locally.
• entities[]: filer-entity objects extracted from the EDGAR header. For 10-C the array typically contains a single filer. Each entity carries cik (numeric string), companyName (with the role suffix (Filer)), type (10-C or 10-C/A), act (always "34" for the Securities Exchange Act of 1934), fileNo (SEC file number), filmNo (EDGAR film accession number), irsNo (EIN), sic (industry code with description, occasionally containing raw HTML entities such as &), stateOfIncorporation, fiscalYearEnd formatted as MMDD, and an optional tickers array of Nasdaq symbols. The tickers field is sometimes absent and must be treated as optional.

Document body: the two-section Form 10-C template

Each document-N.txt is the plain-text body of one EDGAR document from the submission. For substantive 10-C filings, the body is the completed Form 10-C transcribed from the SEC's printed template into ASCII. The form is organised into two Roman-numeral sections, and a filing must populate whichever section corresponds to the triggering event. The unused section is left blank, marked N/A or non applicable, or retained as the original underscore-line template.

Section I — Change in Number of Shares Outstanding. Discloses an event in which the issuer's shares outstanding changed by five percent or more relative to the previously reported total. The required fields are:

• Title of the class of security affected (e.g. "Common Stock").
• Number of shares outstanding before the change.
• Number of shares outstanding after the change.
• Effective date of the change.
• Narrative description of the transaction that produced the change.

Transactions reported under Section I span the standard mechanisms by which Nasdaq issuers altered share counts in this period: stock splits (often expressed as 100 percent stock dividends), partial stock dividends (e.g. five percent), treasury-stock acquisitions or repurchases reducing shares outstanding, secondary issuances, and conversions. The narrative is short — typically one to a few sentences identifying the corporate action.

Section II — Change in Name of Issuer. Discloses a change in the issuer's legal name. The required fields are:

• Former name of the issuer.
• New name of the issuer.
• Effective date of the name change.

A single 10-C may complete only Section I, only Section II, or — when both events occurred together — both sections. The form closes with a signature block carrying the issuer's name, the title of the signing officer, the signing date, and a typewritten or /s/ electronic signature.

File format

Documents are 7-bit ASCII text reflecting mid-1990s EDGAR conventions. They contain no HTML, no PDF, and no embedded images. Layout is achieved through whitespace, underscore lines for fill-in fields, and monospace alignment, occasionally disturbed by stray tab characters from the original word-processing source. Some documents include the EDGAR <PAGE> token as a page-break marker between printed pages; this is the only SGML-style tag that appears inside document bodies and is a paginated-print artefact rather than structural markup.

The full SGML <DOCUMENT><TYPE>...<TEXT>...</TEXT></DOCUMENT> wrapper that originally enveloped each document on EDGAR is stripped during ingestion. It survives at the URL referenced by linkToTxt, while the dataset stores the unwrapped inner text as document-N.txt.

Form lifecycle and 10-C versus 10-C/A

Because the form was created and retired within a single, short, ASCII-only filing era, there is no internal evolution of required content, no shift from text to HTML, and no introduction of structured data across the dataset's lifetime — the template is essentially constant. Amendments are filed as Form 10-C/A and follow the identical two-section template; the structural distinctions are the /A suffix in formType and in entities[].type, and the fact that an amendment re-states the corrected fields of an earlier filing. Both 10-C and 10-C/A are present in the dataset.

Included and excluded content

Each accession folder includes the structured metadata.json and every textual document from the original EDGAR submission, sequentially numbered. Excluded from the per-record folder are images of any kind (graphics, scanned signature pages, logos) and the outer SGML submission wrapper. The full submission text file remains accessible by URL via linkToTxt and via the trailing entry of documentFormatFiles[], but is not duplicated into the container. Because 10-C bodies of this era are essentially text-only, the practical effect of these exclusions is minimal: the substantive content of the filing is fully captured by document-N.txt.

Interpretation notes

A few nuances matter for downstream parsing. Document filenames on disk are normalised to document-<sequence>.txt and do not preserve the original EDGAR filename — the join key back to EDGAR identity is the sequence field of documentFormatFiles[]. Filings that report only one of the two events leave the other section as blank, N/A, non applicable, or untouched underscore-line template, and extractors must handle all four conventions. Share-count fields in Section I are written as filer-formatted strings (with thousands separators and occasional inline commentary) and are not pre-parsed into numeric form. The tickers array on entities[] is optional and may be absent for issuers whose Nasdaq symbol was not captured in the EDGAR header. The sic description string can include raw HTML entities such as & and may need entity-decoding before display. The <PAGE> page-break token, where it appears, should be treated as a layout marker rather than a content boundary. Finally, the periodOfReport field reports the effective date of the underlying corporate event, not the filing-acceptance date; for share-count changes it aligns with the effective date disclosed in Section I, and for name changes with the date in Section II.

How Form 10-C Differs From Similar SEC Datasets

Form 10-C's two narrow triggers — a 5%-or-greater change in outstanding shares of the Nasdaq-quoted class, and a change in issuer name — sit at the boundary of several adjacent SEC reporting regimes. Its closest comparators are the forms that absorbed those triggers after August 1997, plus several look-alikes that share share-count or registration vocabulary but report different events, by different filers, on different timelines.

Form 8-K (current and historical item structure)

• Filer: any Exchange Act reporting issuer, all listing venues. 10-C: Nasdaq-quoted issuers only.
• Trigger: dozens of enumerated current-report events. 10-C: only two.
• Disclosure content (post-2004 8-K): name changes via Item 5.03 (Amendments to Articles of Incorporation or Bylaws); share-rights and recapitalization events via Item 3.03 (Material Modification to Rights of Security Holders); residual share-count events under Item 8.01 (Other Events).
• Disclosure content (1994-1997 8-K, the era contemporaneous with 10-C): the older Items 1-9 taxonomy (changes in control, acquisitions/dispositions, bankruptcy, change in auditors, resignations, financial statements, other events, change in fiscal year), with no dedicated item for routine share-count changes. That gap is precisely why 10-C existed as a Nasdaq-specific filler.
• Timing: 8-K is generally due within four business days; 10-C had a 10-day window.
• Status: 8-K is current and ongoing. 10-C is closed at August 1997. For the 1994-1997 Nasdaq record of name and share-count changes, 10-C is authoritative; from August 1997 forward, 8-K is.

Form 10-Q and Form 10-K (cover-page shares-outstanding)

The cover pages of 10-Q and 10-K disclose outstanding share counts as of a date close to the filing, on a recurring schedule. Strengthening that disclosure is what made a separate Nasdaq-only share-change notice unnecessary.

• Filer: all reporting issuers. 10-C: Nasdaq-quoted issuers only.
• Trigger: fixed quarterly/annual reporting dates, regardless of whether shares moved. 10-C: a discrete corporate event crossing the 5% threshold.
• Content: comprehensive periodic reports (financial statements, MD&A, risk factors); the share count is a single cover-page line. 10-C: a short single-purpose notice with a brief description of the share-changing transaction and no financials.
• Use: Form 10-Q/Form 10-K give continuous tracking at fixed dates; 10-C gives event-anchored point-in-time precision around a specific split, recapitalization, or large issuance during 1994-1997.

Form 10-K/A and Form 10-Q/A vs. Form 10-C/A

All three are amendments, but the scope is incomparable. Form 10-K/A and Form 10-Q/A typically restate financial statements, segment data, or omitted exhibits, with broad analytical implications. 10-C/A corrected discrete fields in a short prior notice (share counts, effective dates, transaction descriptions). Same suffix, very different remediation.

Forms 8-A and 8-B (registration, not change reporting)

• Form 8-A: registers a class of securities under Section 12(b) or Section 12(g), typically tied to exchange listing or crossing the 12(g) holder/asset thresholds. Filed by the issuer; remains active. (Form 8-A)
• Form 8-B: historical successor-issuer registration form, used by a successor (often a new holding company) to adopt the predecessor's registration; largely supplanted by 8-A.
• Contrast with 10-C: 8-A/8-B establish or transfer the registration relationship for a class of securities. 10-C reported a quantitative change in shares already outstanding of an already-registered class, or a name change of an already-registered issuer. They co-occur around restructurings but record different facts.

Form 144 (Rule 144 affiliate resales)

• Filer: the affiliate or other holder of restricted/control stock proposing to sell. 10-C: the issuer.
• Trigger: a planned secondary-market sale above Rule 144 thresholds. 10-C: an issuer-level change in shares outstanding.
• Content: shares to be sold, broker, acquisition history of the holder's lot. Form 144 says nothing about total shares outstanding; 10-C said nothing about insider resales. The only overlap is that both mention share counts.

NYSE and AMEX equivalent obligations

10-C did not cover all listed issuers. It applied solely to Nasdaq-quoted issuers under Rules 13a-17 and 15d-17. NYSE and AMEX issuers met analogous share-count and name-change obligations through exchange rules (for example, NYSE Listed Company Manual provisions on supplemental listing applications and notice requirements), filed with the exchange rather than the SEC. Those notices do not appear in EDGAR as 10-C filings, so 10-C is exhaustive for Nasdaq during 1994-1997 but silent for NYSE and AMEX.

Form 25 (delisting / deregistration)

• Filer: the exchange, or since 2005 sometimes the issuer.
• Trigger: removal of a class from exchange listing and, where applicable, deregistration under Section 12(b).
• Content: identification of the delisted security and the rule basis. 10-C reported events during a continuing Nasdaq quotation; Form 25 ends the listing. Both touch the security lifecycle but at opposite ends. Form 25 remains active.

Forms 3, 4, and 5 (Section 16 insider reports)

• Filer: directors, officers, and >10% beneficial owners. 10-C: the issuer.
• Trigger: Form 3 on insider status; Form 4 within two business days of a reportable transaction; Form 5 as an annual catch-up. 10-C: a 5% issuer-level change in shares outstanding, or a name change.
• Content: the insider's personal holdings and trades. A Form 4 sale of 100,000 shares does not change shares outstanding and would not have triggered 10-C; conversely, a stock split or large primary issuance triggering 10-C generally produces no Form 4 unless an insider is a direct counterparty.

Schedule 13D and Schedule 13G (beneficial ownership)

• Filer: any person or group acquiring more than 5% of a voting class. 10-C: the issuer.
• Trigger: crossing the 5% ownership threshold (Schedule 13D for active intent, Schedule 13G for passive/qualified holders). 10-C: a 5% change in the count of shares outstanding.
• Content: holder identity, position size, source of funds, and (13D) purpose. The shared "5%" is coincidental: 13D/13G tracks accumulation of existing securities by an outside holder; 10-C tracked the issuer's own change in supply. Neither implies the other.

Boundary summary

Form 10-C is distinguished from every nearby dataset on at least one of three axes: filer (issuer, not holder or insider), trigger (issuer-level 5% share-count change or name change), and venue scope (Nasdaq-quoted only). It is further bounded in time to January 1994 through August 1997. For that window and that population it is the authoritative primary source; outside it, the same disclosures live in 8-K (Items 3.03, 5.03, 8.01), in the 10-Q/10-K cover-page share counts, and in their respective amendments, not in any continuation of the 10-C series.

Who Uses the Form 10-C Files Dataset

Because Form 10-C was discontinued in August 1997, this corpus is consumed as historical primary-source evidence rather than for live monitoring. Its users are specialists who need clean point-in-time records of Nasdaq issuer name changes and five-percent share-count movements in the 1994 to 1997 window.

Academic finance and corporate-governance researchers

Used as a clean panel of share-change and identity-change events for studies of 1990s Nasdaq market structure, splits, repurchases, and rename signaling during the dot-com naming boom. filedAt and effective-date anchor event windows; shares-before and shares-after quantify the action; description-of-change lets researchers classify the underlying transaction (split, stock dividend, secondary offering, exchange, repurchase, conversion). cik and ticker join to returns databases for abnormal-return event studies; sic supports industry cross-sections.

Event-study quants and historical-backtest desks

Quants reconstructing 1990s Nasdaq backtests need point-in-time shares outstanding to compute market cap and per-share metrics without lookahead bias. They key on accessionNo, timestamp with filedAt, and apply shares-before / shares-after deltas as a corrections layer over vendor share-count tables. old-name / new-name pairs feed identifier-mapping pipelines that stitch price and fundamental series across rename events.

Securities-litigation support analysts

Disclosure counsel and litigation-support teams working class actions, fraud matters, or successor-liability disputes with damages periods reaching into the mid-1990s cite accessionNo and filedAt for chain-of-custody, quote description-of-change to characterize the corporate action in pleadings, and use old-name / new-name history to establish which present-day entity inherits a 1990s registrant's obligations. Output: exhibits, expert damages reports, and discovery responses on contested pre-1998 share or naming history.

Reference-data and security-master operations

Reference-data teams at fund administrators, index providers, and financial-data vendors validate and repair historical security master records against primary filings. They ingest cik, ticker, old-name, new-name, effective-date, shares-before, and shares-after to reconcile vendor corporate-action histories, backfill CUSIP-to-ticker-to-name linkages, and produce audit trails when downstream clients challenge a historical identifier mapping.

M&A successor-entity and corporate-history researchers

Restructuring advisers and deal-archaeology consultants trace predecessor-issuer chains through sequences of renames, often during due diligence on shell-company reuse, reverse-merger pipelines, or contested successor-liability claims. They walk a cik forward in time, joining each filing's old-name to the prior filing's new-name, and treat 10-C/A amendments as corrections of earlier rename disclosures.

Forensic accountants and valuation experts

Reconstruct share-issuance histories for valuation disputes, estate matters, ESOP litigation, and tax controversies. shares-before, shares-after, and effective-date supply per-event deltas to roll share counts forward or backward across 1994 to 1997; description-of-change supports accounting and tax characterization of each issuance.

Market-microstructure and disclosure-regime historians

Researchers documenting SEC reporting practice study how Nasdaq share-count disclosure operated under Rule 13a-17 and 15d-17 before the obligation was absorbed into Form 10-Q and 10-K cover pages. The cleanly bounded corpus supports descriptive work on filing frequency, amendment rates (the 10-C/A subset), and industry concentration via sic distributions.

Legacy-compliance and records-management teams

Law-firm records groups and corporate secretariats with continuing indemnification, rep-and-warranty, or retention obligations tied to pre-1998 issuers use the dataset as a self-contained archive. The metadata plus original EDGAR documents form a defensible reference set for information requests, audit inquiries, and regulator follow-ups on long-dormant registrants.

Retrieval-system and entity-resolution engineers

Teams building retrieval and extraction systems over historical SEC corpora use the dataset as a small, well-bounded slice for training and evaluation. Useful for extracting structured corporate-action events from narrative description-of-change text, benchmarking entity resolution across old-name / new-name transitions, and testing identifier-linkage models that reconcile cik, ticker, and historical issuer names.

Practical Use Cases

Each use case below ties to specific fields in metadata.json and the Section I / Section II body of document-N.txt.

Point-in-time share-count reconstruction for 1990s Nasdaq event studies

Quants and academic researchers rebuild lookahead-free shares-outstanding panels for January 1994 through August 1997 by sequencing every Section I event for a given issuer. Records are keyed on entities[].cik and ordered by periodOfReport (the effective date) rather than filedAt; Section I's shares-before and shares-after lines supply the delta, and the narrative description-of-change classifies the action as a split, 100% stock dividend, repurchase, secondary, or conversion. Output: a per-CIK shares-outstanding time series used as a corrections layer over vendor share-count tables before computing market cap, abnormal returns, or per-share metrics.

Predecessor-successor name-change graph for Nasdaq issuers

Reference-data teams and corporate-history researchers build a directed rename graph by walking each Section II filing for a stable cik, joining the old-name on filing N to the new-name on filing N-1. entities[].tickers (where present), fileNo, and irsNo carry the identity through the rename, and 10-C/A records are folded in as corrections to earlier Section II disclosures. Output: a CIK-anchored predecessor-successor edge list used to backfill CUSIP-to-ticker-to-name lineage in security masters and to stitch price and fundamental series across 1990s identifier breaks.

Securities-litigation timeline reconstruction for 1994-1997 damages periods

Litigation-support analysts working class actions, successor-liability disputes, or restatement matters with damages windows reaching into the mid-1990s cite accessionNo and filedAt for chain-of-custody, quote the Section I description-of-change verbatim to characterize a contested corporate action, and use Section II's old-name / new-name / effective-date triple to establish which present-day entity inherits a registrant's pre-1998 obligations. Output: exhibits, expert reports, and discovery productions grounded in primary EDGAR text rather than secondary summaries.

Sector-level mining of 5% share-change events

Market-structure historians study the frequency and composition of large share-count moves across the dot-com run-up by grouping Section I events on entities[].sic (after entity-decoding &-style artefacts) and periodOfReport. Description-of-change text is classified into split / stock-dividend / repurchase / secondary / conversion buckets; shares-before and shares-after produce the percentage move. Output: SIC-by-year tabulations of split intensity, repurchase activity, and dilutive-issuance frequency for the narrow Nasdaq window where 10-C is the authoritative source.

Forensic share-issuance reconstruction for old M&A and valuation disputes

Forensic accountants and valuation experts handling estate, ESOP, tax-controversy, or post-merger restatement matters roll share counts forward or backward across 1994-1997 using each filing's shares-before, shares-after, and effective-date as a per-event delta. The Section I narrative supports accounting and tax characterization of each issuance; 10-C/A amendments are applied as corrections to the prior 10-C they supersede. Output: defensible reconstructed cap-table movements admissible as expert exhibits.

LLM and RAG retrieval over a complete primary-source slice

Retrieval and extraction engineers use the dataset as a small, fully bounded corpus for training and benchmarking. The flat ZIP-per-month layout, predictable two-section ASCII template, and structured metadata.json (with accessionNo, filedAt, cik, sic, tickers) make it well suited to evaluating extractors that pull shares-before, shares-after, effective-date, old-name, and new-name out of narrative document-N.txt bodies, and to benchmarking entity resolution across old-name / new-name transitions. Output: labelled extraction sets, retrieval-quality scores, and entity-linkage models tuned for historical SEC text.

Dataset Access

The Form 10-C Files Dataset is available through three access patterns: a JSON index endpoint for metadata discovery, a single archive download for the full dataset, and per-container downloads for incremental retrieval. The full dataset and individual container endpoints require an SEC API key, passed either as a token query parameter or via an Authorization header.

Dataset Index JSON API: https://api.sec-api.io/datasets/form-10c-files.json

This endpoint returns dataset-level metadata and the full container manifest. It does not require an API key. The response includes the datasetId, name, description, updatedAt, earliestSampleDate, totalRecords, totalSize, formTypes, containerFormat, fileTypes, and a containers array. Each container entry exposes its downloadUrl, key (in YYYY/YYYY-MM.zip form), size, records, and updatedAt timestamp. Polling this index lets you detect which monthly containers were touched by the most recent refresh and download only those that changed.

          1
          {
        

          2
            "datasetId": "1f13365b-9ae0-6997-859d-601d1c25bd3e",
        

          3
            "datasetDownloadUrl": "https://api.sec-api.io/datasets/form-10c-files.zip",
        

          4
            "name": "Form 10-C Files Dataset",
        

          5
            "updatedAt": "2026-04-15T11:59:27.447Z",
        

          6
            "earliestSampleDate": "1994-01-01",
        

          7
            "totalRecords": 1342,
        

          8
            "totalSize": 2751521,
        

          9
            "formTypes": ["10-C", "10-C/A"],
        

          10
            "containerFormat": "ZIP",
        

          11
            "fileTypes": ["TXT", "JSON"],
        

          12
            "containers": [
        

          13
              {
        

          14
                "downloadUrl": "https://api.sec-api.io/datasets/form-10c-files/1997/1997-08.zip",
        

          15
                "key": "1997/1997-08.zip",
        

          16
                "size": 41238,
        

          17
                "records": 12,
        

          18
                "updatedAt": "2026-04-15T11:59:27.447Z"
        

          19
              }
        

          20
            ]
        

          21
          }
        

Fetch the index with curl:

curl https://api.sec-api.io/datasets/form-10c-files.json

Download Entire Dataset: https://api.sec-api.io/datasets/form-10c-files.zip?token=YOUR_API_KEY

This endpoint returns the complete dataset as a single ZIP archive covering all Form 10-C and Form 10-C/A filings from January 1994 through the form's discontinuation in August 1997. Because the dataset is compact, a one-shot download is usually the simplest approach. An API key is required.

curl -o form-10c-files.zip "https://api.sec-api.io/datasets/form-10c-files.zip?token=YOUR_API_KEY"

Download Single Container: https://api.sec-api.io/datasets/form-10c-files/1997/1997-08.zip?token=YOUR_API_KEY

Containers are organized by year/year-month.zip and let you fetch a single month of filings without pulling the full archive. Use this pattern when reacting to specific updatedAt changes reported by the index. An API key is required.

curl -o 1997-08.zip "https://api.sec-api.io/datasets/form-10c-files/1997/1997-08.zip?token=YOUR_API_KEY"

Frequently Asked Questions

When was Form 10-C in effect?

The dataset spans the full active life of Form 10-C in EDGAR, from January 1994 through the form's discontinuation in August 1997. Pre-EDGAR paper filings of Form 10-C are not included.

Who was required to file Form 10-C?

Issuers — and only issuers — with a class of equity securities quoted on the Nasdaq interdealer quotation system, including the Nasdaq National Market and Nasdaq SmallCap Market. The filer had to be an Exchange Act reporting company under Section 13 or Section 15(d). Issuers listed on NYSE or AMEX, traded on the pink sheets, or reporting as foreign private issuers on Form 20-F were outside the population, as were transfer agents, market makers, Nasdaq itself, and shareholders.

What events triggered a Form 10-C filing?

Two events, each independently sufficient: a cumulative change of 5 percent or more in the number of shares outstanding of the Nasdaq-quoted class (measured against the most recently reported share count), or a change in the issuer's legal name. Both could be reported on a single Form 10-C when they coincided. The filing was due within 10 days after the close of the calendar quarter in which the triggering event occurred.

Why was Form 10-C discontinued?

The SEC eliminated Form 10-C in August 1997 because its content had become duplicative. Outstanding-share counts for each class of common equity were already reported on the cover pages of Forms 10-Q and 10-K, and issuer name changes had become reportable as a current report on Form 8-K. Removing Form 10-C eliminated the parallel Nasdaq-specific channel without reducing the information available to investors.

How does Form 10-C relate to today's Form 8-K Item 5.03?

After August 1997, the disclosures Form 10-C carried migrated to Form 8-K. In the post-2004 8-K item structure, name changes are reported via Item 5.03 (Amendments to Articles of Incorporation or Bylaws), share-rights and recapitalization events via Item 3.03 (Material Modification to Rights of Security Holders), and residual share-count events under Item 8.01 (Other Events). For the 1994-1997 Nasdaq record of name and share-count changes, however, Form 10-C is the authoritative primary source — there is no continuation of the 10-C series in 8-K for that window.

What file formats does the dataset use?

Each accession folder contains exactly one metadata.json (structured JSON following the SEC-API submission schema) plus one or more document-N.txt files (7-bit ASCII text reflecting mid-1990s EDGAR conventions, with no HTML, PDF, or embedded images). The dataset is distributed as ZIP containers partitioned by year and month in the form YYYY/YYYY-MM.zip.

How do I download the dataset?

Three access patterns are available: the public JSON index at https://api.sec-api.io/datasets/form-10c-files.json (no API key required) for dataset-level metadata and the container manifest; the full archive at https://api.sec-api.io/datasets/form-10c-files.zip?token=YOUR_API_KEY for a one-shot download; and per-month containers at https://api.sec-api.io/datasets/form-10c-files/YYYY/YYYY-MM.zip?token=YOUR_API_KEY for incremental retrieval. The full-dataset and per-container endpoints require an SEC API key.

What does one record represent?

One record is a single Form 10-C or Form 10-C/A submission to EDGAR, addressed by its SEC accession number. The unit is the entire filing as accepted: the parsed EDGAR submission header serialised as metadata.json, plus every textual document EDGAR distributed under that accession, written to disk as one or more document-N.txt files. Image attachments from the original submission are excluded by design.