The Form ATS-N Files Dataset is the complete EDGAR corpus of public manner-of-operations disclosures filed by broker-dealer operators of NMS Stock Alternative Trading Systems under Rule 304 of Regulation ATS. Each record is one EDGAR submission of Form ATS-N — an initial filing, a material amendment, a non-material updating amendment, or a correcting amendment — packaged as an accession-numbered folder containing the canonical XML form, the EDGAR-rendered XHTML view, the PDF exhibits, and a pipeline-authored metadata.json wrapper. Coverage begins with the earliest Rule 304 filings in May 2019 and continues forward, giving a structured, public window into how every off-exchange equity venue running NMS stock matching describes its order types, subscriber tiers, affiliate handling, fees, and information-barrier safeguards.
Programmatically retrieve the full list of dataset archive files, download URLs and dataset metadata.
Dataset Index JSON API
Download the entire dataset as a single archive file.
Download Entire Dataset:
Download a single container file (e.g. monthly archive) from the dataset.
Download Single Container:
The dataset captures every Form ATS-N submission accepted by EDGAR since the form became operative in early 2019, distributed as monthly ZIP containers. Form ATS-N is the public disclosure form mandated by Rule 304 of Regulation ATS for any alternative trading system that transacts in NMS stocks (exchange-listed equities and certain ETFs). It was created by the SEC's 2018 Regulation ATS-N rulemaking (Release No. 34-83663) and supplements — it does not replace — the legacy confidential Form ATS: an NMS Stock ATS that also trades non-NMS securities continues to file Form ATS for the non-NMS-stock side of its business, while Form ATS-N covers the NMS-stock activity in a public, structured form.
Unlike legacy Form ATS, Form ATS-N is filed and disseminated through EDGAR using a structured XML schema in the http://www.sec.gov/edgar/atsn namespace, and its narrative answers are intended to be read by subscribers, market participants, and regulators to assess order-handling practices, conflicts of interest arising from the broker-dealer operator's other business lines, segmentation and tiering of order flow, fees, market data ingestion, and the safeguards adopted around confidential subscriber trading information. The form is laid out as a Cover followed by four numbered Parts (I through IV), with exhibits either attached to the submission or — by checkbox election — hosted on the operator's own website. The dataset preserves XML (the structured form), JSON (the metadata wrapper), and PDF (exhibits); image files are excluded.
The submission types that populate this dataset are:
ATS-N — initial filing under Rule 304(a)(1)(i)ATS-N/MA — material amendment under Rule 304(a)(2)(i)(A), filed before implementing a material changeATS-N/UA — updating amendment under Rule 304(a)(2)(i)(B), filed for non-material changesATS-N/CA — correcting amendment under Rule 304(a)(2)(i)(C), correcting prior errorsThe description field in the metadata wrapper typically tags the regulatory cite alongside the flavor (for example Form ATS-N - Initial Form ATS-N (Rule 304(a)(1)(i))).
One record is a single EDGAR submission of Form ATS-N, identified by an 18-digit accession number and materialized on disk as an accession-numbered folder packed inside a monthly ZIP container. The folder bundles every document the registrant submitted to EDGAR for that accession — the canonical XML form, the EDGAR-rendered XHTML view of the same form, any exhibit attachments, and a pipeline-authored metadata.json wrapper — with image files excluded. Because Form ATS-N is the manner-of-operations disclosure for an NMS Stock ATS, each record is a point-in-time snapshot of how one alternative trading system runs: an initial registration, a material amendment proposing operational changes, a non-material updating amendment, or a correcting amendment fixing a prior error.
Each accession folder is named with the 18-digit accession number with hyphens stripped (for example 000072468319000030). The folder contains:
metadata.json — the filing-level wrapper authored by the dataset pipeline, summarizing the EDGAR header and listing every document in the submission with its EDGAR exhibit-type code, byte size, and live SEC URL.primary_doc.xml (at the accession root) — the canonical, machine-readable Form ATS-N XML. This is the authoritative representation of the filing.xslATS-N_X01/primary_doc.xml — the same submission transformed by EDGAR's ATSN_print.css stylesheet into a printable XHTML view. Despite the .xml extension, the file is HTML content that begins with <!DOCTYPE html> and is the rendering EDGAR shows to a browser visitor.I_Form_BD_ScheduleA.pdf, I_Form_BD_ScheduleB.pdf).The metadata.json wrapper is the bridge between the raw filenames on disk and the EDGAR exhibit-type vocabulary: its documentFormatFiles[] array assigns each file to a code such as ATS-N (the primary form, listed once for the rendered XHTML URL and once for the raw XML), ATS-N EX-1 SCHD A BD (Form BD Schedule A copy), ATS-N EX-2 SCHD B BD (Form BD Schedule B copy), and similar codes for additional exhibits. A trailing entry with empty sequence and type represents the SGML "Complete submission text file" that EDGAR generates from the submission; that SGML wrapper is referenced by URL but is not stored on disk, since the structured XML and rendered XHTML supersede it.
metadata.json carries the descriptive layer for the filing:
formType — one of ATS-N, ATS-N/MA, ATS-N/UA, ATS-N/CA.accessionNo — the dashed accession number (for example 0000724683-19-000030).description — the EDGAR-produced label identifying the filing flavor and the Rule 304 cite.filedAt — ISO-8601 timestamp with timezone offset, recording EDGAR acceptance time.linkToFilingDetails, linkToTxt, linkToHtml, linkToXbrl — canonical SEC URLs for the rendered form, the SGML submission text, the EDGAR HTML index page, and any XBRL exhibit. linkToXbrl is empty across this dataset because Form ATS-N is not an XBRL-bearing filing.documentFormatFiles[] — one entry per included document, each with sequence, size (bytes), documentUrl, type (the EDGAR exhibit-type code), and an occasional description.entities[] — filer information lifted from the EDGAR header: companyName (suffixed (Filer)), cik, fileNo, irsNo, stateOfIncorporation, fiscalYearEnd, act, filmNo, and an echoed type.id — an opaque dataset-internal record hash.seriesAndClassesContractsInformation, dataFiles — empty arrays inherited from the broader EDGAR record schema; they have no content for ATS-N.The entities[] array describes the broker-dealer operator filing the form, not the ATS itself; the ATS's marketing name and identifiers must be read from the Cover and Part I of the structured XML.
primary_doc.xml is rooted at <edgarSubmission> in the http://www.sec.gov/edgar/atsn namespace, with companion namespaces http://www.sec.gov/edgar/common (com:) and http://www.sec.gov/edgar/atsncommon (ats:). It is divided into a <headerData> block and a <formData> body that mirrors the regulatory structure of the form.
<headerData> carries operational metadata for the EDGAR submission itself: <submissionType> (the form-type code), <filerInfo> with <liveTestFlag>, <filer><filerCredentials> (containing <com:cik> and the masked <com:ccc>), and a <flags> block with ats:overrideInternetFlag and ats:confirmingCopyFlag. This block governs how EDGAR processes the submission and is not part of the public form text per se.
<formData> carries the form proper: a <cover> element followed by <partOne>, <partTwo>, <partThree>, and <partFour>. The schema uses a strict element-naming convention that allows every field to be tied back to a specific Item in the regulatory form:
rb... denotes a radio-button Y/N answer.cb... denotes a checkbox boolean.tx... and txt... denote short free-text inputs.ta... denotes a long text area used for narrative answers.rbPart1Item1IsBd, txPart1Item4aBdFileNumber, taPart3Item1SubscriberType, cbPart1Item8Exhibit1atWebsite.<part2Item1aArePermittedToEnterInterest rbPart2Item1aArePermittedToEnterInterest="Y"><taPart2Item1aUnitNamesEnterInterest>...</taPart2Item1aUnitNamesEnterInterest></part2Item1aArePermittedToEnterInterest>.<atsNames> parent with repeated <atsName> children, or repeated <taPart3Item1SubscriberType> children.The <cover> element captures the front-page identifiers of the form: txNMSStockATSName (the marketing name of the ATS) and rbOperatesPursuantToFormATS (a Y/N flag indicating whether the entity also operates an ATS under the legacy Form ATS framework for non-NMS-stock activity). The Cover is short but it is the connective tissue between the EDGAR header (which identifies the broker-dealer operator) and the form body (which describes the ATS itself).
Part I gathers the identity of the ATS and its broker-dealer operator and is dominated by short structured fields:
rbPart1Item1IsBd).txPart1Item2ATSName).<atsName> entries inside <atsNames>.txPart1Item4aBdFileNumber, txPart1Item4aBdCrdNumber).txPart1Item5aNsaFullName, part1Item5bEffectiveMembershipDate, txtPart1Item5cNmsStockMPID).<part1Item7PrimarySite> with ats:street1, ats:city, ats:state, ats:zip).cbPart1Item8Exhibit1atWebsite, cbPart1Item9Exhibit2atWebsite) electing whether Exhibits 1 and 2 (the Form BD Schedule A and Schedule B copies) are reproduced on the filer's website rather than attached.Part II is the conflicts-of-interest disclosure block. Its items cover trading activities of the broker-dealer operator on the ATS, trading by affiliates, the availability and mechanics of subscriber opt-outs from interacting with operator or affiliate flow, arrangements with other trading centers, other products and services that the operator offers in connection with the ATS, the use of service providers (and any sharing of confidential trading information with them), and the written safeguards and procedures the operator has adopted to protect confidential subscriber trading information.
Each Item is encoded either as a single Y/N flag (for example rbPart2Item3aCanSubscrOptOutWithOATIOfBD) or as a flag-plus-narrative container, with the narrative carried in long ta... text-area children. The free-text disclosures — especially the safeguards-and-procedures answer — are the analytical heart of Part II and frequently run to thousands of words describing information barriers, access controls, and monitoring practices.
Part III is the longest and most operationally detailed section of Form ATS-N. Its items walk through the full life of an order on the ATS and cover, broadly:
Multi-valued items are encoded as repeated elements (each subscriber type appears as its own <taPart3Item1SubscriberType> child, and so on), and several items use a companion rb... flag asking whether the answer is the same for all subscribers, with conditional narrative children when treatment differs. The structured XML element names are uniform across operators, but the narrative content reflects each ATS's unique market design, so Part III is where the bulk of policy-relevant text lives and where cross-operator variation is greatest.
Part IV closes the form with a contact for ATS-N inquiries, the signature of the filing officer, the officer's title, the date of signing, and the broker-dealer operator's consent to service of process. In the structured XML it appears as <partFour>, the final container after <partThree>; the XHTML rendering surfaces it as the final entry in its hyperlinked Contents block.
The exhibit set for Form ATS-N is small but informative, and the dataset preserves whatever was attached to the EDGAR submission other than image files. The recurring exhibit codes are:
ATS-N EX-1 SCHD A BD) — a copy of the broker-dealer operator's Form BD Schedule A (direct owners and executive officers).ATS-N EX-2 SCHD B BD) — a copy of the broker-dealer operator's Form BD Schedule B (indirect owners).Exhibits are typically delivered as standard PDF binaries at the accession root with descriptive filenames such as I_Form_BD_ScheduleA.pdf. The operator can elect to publish Exhibit 1 and Exhibit 2 on its own website in lieu of attaching them; in that case the cover-page checkboxes (cbPart1Item8Exhibit1atWebsite, cbPart1Item9Exhibit2atWebsite) are set, no PDF is included in the submission, and the website URL for the exhibit appears in the form text.
The xslATS-N_X01/primary_doc.xml file is the EDGAR-produced human-readable view of the same submission, generated by EDGAR's ATSN_print.css stylesheet. It opens with the SEC's standard disclaimer ("THE SECURITIES AND EXCHANGE COMMISSION HAS NOT PASSED UPON THE MERITS OR ACCURACY OF THE DISCLOSURES IN THIS FILING."), continues with a hyperlinked Contents block whose anchors link to every Part and Item, and then renders each Item with check-box and radio-button images alongside the operator's narrative answers. It is the same content as primary_doc.xml but reformatted for visual review and convenient HTML scraping.
For each accession the dataset preserves the canonical XML form, the rendered XHTML view, the metadata wrapper, and every non-image exhibit document submitted to EDGAR. The structured XML carries the entirety of the regulated form text in a fully parseable shape, so for most analytical workflows the XML alone is sufficient and the XHTML is a convenience artifact for human review.
documentUrl in metadata.json but is not materialized on disk; the structured XML and rendered XHTML cover the same content.<prefix>Part<N>Item<n><letter>... element name, so a parser can map XML nodes to the SEC's published Item labels without natural-language matching.ta... child. Treat the flag and narrative as separate fields to avoid losing either signal.cbPart1Item8Exhibit1atWebsite or cbPart1Item9Exhibit2atWebsite is set, the absence of the corresponding PDF is an explicit operator election, not a missing file.ATS-N/MA, ATS-N/UA, or ATS-N/CA in isolation may leave gaps that can only be filled by joining to the most recent prior filing for the same ATS — Part III in particular often shows only the items being amended, with the rest implicitly carried forward. Reconstructing the operative state of an ATS at a given moment generally requires walking the filing chain forward from the initial ATS-N.entities[] block in metadata.json describes the broker-dealer operator (the EDGAR filer), not the ATS. The ATS's marketing name and MPID must be read from <cover> and <partOne> of the XML.Each Form ATS-N is submitted by a single broker-dealer that operates an alternative trading system trading NMS stocks (exchange-listed equities and certain ETFs). These venues are referred to as "NMS Stock ATSs."
The legal filer is the broker-dealer operator, not the ATS itself. Under Regulation ATS, an ATS is not a separately registered entity; it is operated by a broker-dealer registered with the Commission under Section 15 of the Securities Exchange Act of 1934 and a member of FINRA. The filing identifies both the ATS (market name, identifying details) and the broker-dealer operator (CIK, CRD, SEC file number), but the disclosure obligation rests on the broker-dealer.
The dataset population consists of registered broker-dealer operators of NMS Stock ATSs: bank-affiliated broker-dealers, agency brokers, and independent equity venues running dark pools, midpoint crossing networks, conditional order systems, and other off-exchange equity matching venues.
Form ATS-N exists under Rule 304 of Regulation ATS, adopted in Release No. 34-83663 (July 18, 2018). The 2018 amendments imposed enhanced public-disclosure requirements specifically on NMS Stock ATSs, replacing the historically confidential Form ATS regime for this venue class. Effective Form ATS-N filings are posted publicly on the Commission's website so subscribers and market participants can evaluate order handling, conflicts, segmentation and tiering, fees, market data usage, and affiliate activity. The first filings appeared on EDGAR in early 2019; the dataset's earliest records date to May 2019.
Form ATS-N is filed in four distinct flavors, each driven by a different event:
Initial Form ATS-N — Filed by an entity that intends to begin operating as an NMS Stock Alternative Trading Systems (or that was already operating when Rule 304 took effect). Must be submitted before the ATS commences NMS-stock operations. The Commission has up to 120 days (extendable another 120 with consent) to declare the form effective or institute ineffectiveness proceedings; the ATS may not operate as an NMS Stock ATS until effectiveness.
Form ATS-N/MA (Material Amendment) — Filed when the broker-dealer operator proposes a material change to the manner of operation, to operator or affiliate activities with respect to the ATS, or to other previously disclosed information. Examples include changes to order types, matching logic, subscriber categories, segmentation, or affiliate handling. Must be filed at least 30 calendar days before the proposed implementation, and the change cannot be implemented until the amendment is effective.
Form ATS-N/UA (Updating Amendment) — Filed to update non-material information. Aggregates non-material changes occurring within a calendar quarter and must be filed no later than 30 calendar days after quarter-end. No filing is required for a quarter with no non-material changes.
Form ATS-N/CA (Correcting Amendment) — Filed promptly upon discovery that information in a previously filed Form ATS-N was inaccurate at the time of filing. Addresses errors rather than operational changes; no waiting period applies and the correction stands as filed.
The Commission may declare any Form ATS-N or amendment ineffective after notice and hearing, in which case the ATS must cease NMS-stock trading.
Form ATS-N sits in a tight regulatory neighborhood: filings by alternative trading systems and their broker-dealer operators, plus structurally adjacent disclosures from registered exchanges and order-routing intermediaries. The closest comparators are other Regulation ATS forms (ATS, ATS-R), exchange-side equivalents (Form 19b-4, Forms 1 / 1-A / 1-N), the operator-level broker-dealer registration (Form BD), and execution-quality disclosures published outside EDGAR (FINRA OTC ATS data, Rule 605/606 reports).
The Rule 301(b)(2) initial operating notice and amendment vehicle for ATSs trading non-NMS instruments (corporate and municipal bonds, Treasuries, listed options). Filed confidentially with the SEC, not publicly available — the inverse of ATS-N's defining property. Different filer population (non-equities venues), less standardized narrative, and no public access. Not a substitute: use Form ATS for fixed-income and options dark venues, ATS-N for equities.
The numeric, confidential quarterly companion to Form ATS, reporting aggregated volume and transaction counts by security across all ATSs (including NMS Stock ATSs). ATS-N is descriptive and structural ("how the venue works"); ATS-R is quantitative and operational ("how much it traded"). Strictly complementary — neither can be reconstructed from the other.
The public exchange-side analog: national securities exchanges, registered clearing agencies, and FINRA file 19b-4 for each proposed rule change under Section 19(b). Like ATS-N, it discloses order types, matching priority, fees, and access — but rule-by-rule and event-driven, one filing per amendment, rather than ATS-N's holistic venue-level disclosure. Filer populations are mutually exclusive: exchanges file 19b-4, ATSs file ATS-N.
The "what is this venue" filings for entities that chose exchange registration under Section 6 instead of the ATS exemption under Rule 3a1-1. Public and comprehensive like ATS-N, but very infrequent (one substantive filing plus long-tail amendments) and covering legally distinct entity types. Useful as a lit/dark cross-regime comparator; not combinable with ATS-N without reconciling entity status. See Form 1, Form 1-A, and Form 1-N, or the consolidated Forms 1, 1-A, and 1-N overview.
Filed by the broker-dealer entity that operates the ATS. Overlaps with ATS-N only at the operator-identity layer (ownership, affiliates, disciplinary history); says nothing about matching engines, order types, or subscriber tiers. Treat Form BD as supporting context for affiliate-conflict analysis; ATS-N remains the primary source on venue mechanics.
The public counterpart to confidential ATS-R: weekly and monthly aggregated NMS-stock volume per ATS per security, published outside EDGAR. Same filer universe as ATS-N, but purely tabular and quantitative — no overlap in content. Use FINRA OTC ATS Volume Data for market share, ATS-N for venue design.
Reg NMS execution-quality (605, market centers) and order-routing (606, broker-dealers) disclosures. Public, periodic, tabular. They measure the outcomes of routing — effective spreads, fill rates, destinations — while ATS-N describes the structural rules of one such destination. Different abstraction levels (realized performance vs. venue rulebook); strictly complementary.
Form ATS-N is the only SEC filing that combines four properties simultaneously: public, narrative, venue-level, and structural, scoped to NMS Stock ATSs under Rule 304. Form ATS shares the structural narrative form but is confidential and covers non-equities. ATS-R shares the equities-ATS filer population but is confidential and numeric. 19b-4 and Forms 1/1-A/1-N cover exchanges, not ATSs. Form BD covers the operator entity, not the venue. FINRA volume data and Rule 605/606 are public but quantitative and live outside EDGAR. Substitution is effectively impossible; pairing is the norm.
Form ATS-N is the only public, structured account of how NMS Stock Alternative Trading Systems match orders, who can access them, and how operators manage conflicts with affiliates. A narrow set of professionals work the filings closely, each focused on different parts of the record.
Heads of trading at asset managers, pension managers, and hedge funds use Form ATS-N to set and defend dark-pool routing decisions. They read Part III items on subscriber categories, order types, matching priorities, and segmentation or tiering, plus opt-out controls for principal and affiliated flow, minimum size thresholds, and conditional order behavior. Output: venue approval lists, broker routing instructions, and memos justifying inclusion or exclusion of specific pools.
Electronic trading desks, smart-order-router engineers, and execution-services product managers at broker-dealers use the filings to perform venue due diligence and parameterize routing logic. They compare Part III matching methodologies, priority rules, and fee tiers across venues, and lean on Part II disclosures of broker-dealer operator and affiliate activities to govern routing to affiliated venues. Output: SOR weight calibration, periodic venue reviews, and RFP responses to institutional clients.
TCA analysts and best-execution committees use Form ATS-N as the qualitative complement to their fill data. When they see unexpected fill patterns, adverse-selection signatures, or fee anomalies, they go to Part III order-type, matching-logic, segmentation, and fee-schedule items to test whether disclosed mechanics explain the behavior. Output: quarterly best-execution reports, regulatory documentation, and venue scorecards.
Academic and industry researchers studying off-exchange trading mine the corpus to classify matching engine designs, midpoint pricing rules, conditional order handling, tiering systems, and market data inputs across venues, then pair those classifications with trade and quote data to test hypotheses about toxicity and adverse selection. Output: working papers, market-quality studies, and Regulation ATS policy submissions.
Compliance officers and disclosure drafters at broker-dealers operating ATSs benchmark peer filings when preparing or amending their own. They focus on how competitors describe affiliate access, information barriers, safeguards over confidential trading information, market data usage, and personnel access controls. Output: internal redlines, Part III amendments, and policy updates that align operations to disclosure.
Lawyers handling private litigation over dark-pool conduct treat Form ATS-N as core documentary evidence. They contrast disclosed matching logic, subscriber categorization, and Part III safeguards against alleged conduct, and read Part II affiliate-activity items closely, since prior cases have turned on gaps between disclosed and actual handling of affiliated or high-frequency flow. Output: complaint drafting, discovery requests, expert reports, and damages models.
Examination and market structure staff at securities and self-regulatory bodies use Form ATS-N as the baseline they test venue behavior against. They flag outliers in tiering and affiliate access, track amendments that signal operational changes, and check consistency between filed Part II/III disclosures and observed conduct. Output: exam work programs, sweep letters, enforcement referrals, and rulemaking analyses.
Product and engineering teams building venue rating tools, broker scorecards, and routing-optimization software extract structured features from the filings: matching priorities, supported order types, tiering criteria, fee tiers, market data inputs, and affiliate participation flags. These feed dashboards and toxicity or routing models. Output: venue intelligence APIs, customer reports, and analytics product features.
Teams building compliance copilots and trading research assistants index Form ATS-N as a dense, technical corpus to answer queries about how a given ATS handles a specific order type, what counterparties an order can interact with, or how affiliate flow is segregated. Output: retrieval benchmarks, evaluation sets, and production assistants for trading and compliance users.
Concrete workflows that buy-side, sell-side, compliance, research, and analytics teams run against the Form ATS-N corpus.
Parse primary_doc.xml across the most recent ATS-N, ATS-N/MA, and ATS-N/UA filings for every active NMS Stock ATS and project Part III items into structured columns: supported order types, minimum size thresholds, conditional-order and IOI mechanics (Item on conditional orders), segmentation/tiering flags (rb... flags plus the associated ta... narrative), counterparty-selection rules, and the fee-schedule narrative. Output: a per-venue feature table consumed by SOR weight calibration, venue scorecards, and quarterly broker reviews.
Pull every Part II item describing broker-dealer operator trading on the venue, affiliate participation, and subscriber opt-out availability (for example rbPart2Item3aCanSubscrOptOutWithOATIOfBD and the paired narrative). Cross-reference with Exhibit 1 / Exhibit 2 (ATS-N EX-1 SCHD A BD, ATS-N EX-2 SCHD B BD) to surface direct and indirect owners and identify undisclosed corporate affiliations. Output: a venue approval memo flagging pools where principal flow, affiliate flow, or shared service providers cannot be opted out of.
Walk the filing chain for one ATS by CIK and form-type sequence, diffing successive primary_doc.xml documents element-by-element using the deterministic <prefix>Part<N>Item<n>... element paths. Distinguish material amendments (ATS-N/MA) from non-material updating amendments (ATS-N/UA) and corrections (ATS-N/CA), and reconstruct the operative state at any historical date by carrying forward unchanged Items. Output: an audit log of operational changes (new order types added, fee-tier changes, segmentation logic revisions) used by best-execution committees and litigators for "as-of" venue state.
For an operator drafting an amendment, extract the long ta... narrative children under Part II safeguards items (and the corresponding Exhibit 3 / Exhibit 4 PDFs where attached) across peer ATSs. Compare disclosed access controls, monitoring practices, and procedures protecting confidential subscriber trading information. Output: a redline pack for compliance counsel showing how peer venues describe equivalent controls, used to align proposed disclosure with industry practice before filing.
Given an alleged conduct period, pull every Form ATS-N and amendment in force for the named ATS, extract Part II affiliate-activity items, Part III subscriber-category, segmentation, counterparty-selection, and order-display items, and the Part IV signature/officer block. Pair the structured XML answers with the rendered XHTML for exhibits. Output: a chronologically ordered exhibit set tying specific disclosure language to the claim, plus a list of officers who signed each filing for deposition planning.
Index the canonical primary_doc.xml at the Item level (one chunk per ta... narrative, tagged with Part, Item, ATS marketing name from <cover><txNMSStockATSName>, MPID from txtPart1Item5cNmsStockMPID, and filedAt) plus the rendered XHTML for human-readable citations. Output: a retrieval index that answers questions such as "which NMS Stock ATSs allow conditional orders to interact with displayed orders" or "how does venue X segment retail flow", with deep links back to the EDGAR filing.
For academic and policy research, classify each ATS by midpoint vs. limit-book matching, presence of designated liquidity providers, segmentation tiers and notice mechanics, and market data inputs (Part III items on trading services, designated liquidity providers, segmentation, and market data sources). Join the resulting taxonomy to FINRA OTC ATS volume data and TAQ to test hypotheses about adverse selection by venue design. Output: working-paper datasets and Regulation ATS policy submissions.
Use metadata.json entities[] (CIK, file number, IRS number, state of incorporation) plus the Form BD Schedule A / Schedule B copies attached as Exhibits 1 and 2 to assemble a directory of NMS Stock ATS operators with ownership, executive officers, and indirect owners as of each filing date. Output: a reference table that joins operator entity, ATS marketing names (<atsNames> repeated children), MPID, and SRO membership effective date for use in venue-intelligence products and KYC-style operator due diligence.
The Form ATS-N Files Dataset is accessible through three endpoints: a JSON index for metadata and container enumeration, a full archive download, and per-container downloads for incremental retrieval.
Dataset Index JSON API: https://api.sec-api.io/datasets/form-atsn-files.json
Returns dataset-level metadata along with the list of all container files. Each container entry includes key, size, records, and updatedAt, which makes it straightforward to detect which monthly archives changed in the most recent refresh and download only those. This endpoint does not require an API key.
Example response:
1
{
2
"datasetId": "1f13365b-9ae0-6a86-9927-479ed0a840ff",
3
"datasetDownloadUrl": "https://api.sec-api.io/datasets/form-atsn-files.zip",
4
"name": "Form ATS-N Files Dataset",
5
"updatedAt": "2026-04-16T08:59:41.796Z",
6
"earliestSampleDate": "2019-05-01",
7
"totalRecords": 23,
8
"totalSize": 1989000,
9
"formTypes": ["ATS-N"],
10
"containerFormat": "ZIP",
11
"fileTypes": ["XML", "PDF", "JSON"],
12
"containers": [
13
{
14
"downloadUrl": "https://api.sec-api.io/datasets/form-atsn-files/2019-08.zip",
15
"key": "2019-08.zip",
16
"size": 412187,
17
"records": 3,
18
"updatedAt": "2026-04-16T08:59:41.796Z"
19
}
20
]
21
}
Download Entire Dataset: https://api.sec-api.io/datasets/form-atsn-files.zip?token=YOUR_API_KEY
Downloads the complete dataset as a single ZIP archive containing every monthly container from May 2019 to the most recent refresh. This endpoint requires an API key.
Download Single Container: https://api.sec-api.io/datasets/form-atsn-files/2019-08.zip?token=YOUR_API_KEY
Downloads one monthly container by its key (for example 2019-08.zip), which is useful for incremental syncing or backfilling a specific month. This endpoint requires an API key.
The dataset covers Form ATS-N, the public manner-of-operations disclosure mandated by Rule 304 of Regulation ATS for any alternative trading systems that transacts in NMS stocks. It includes all four submission flavors: initial filings (ATS-N), material amendments (ATS-N/MA), non-material updating amendments (ATS-N/UA), and correcting amendments (ATS-N/CA).
One record is a single EDGAR submission of Form ATS-N, identified by an 18-digit accession number and stored as an accession-numbered folder packed inside a monthly ZIP container. Each folder contains the canonical primary_doc.xml form, the EDGAR-rendered XHTML view at xslATS-N_X01/primary_doc.xml, any non-image PDF exhibits, and a pipeline-authored metadata.json wrapper.
Form ATS-N is filed by broker-dealers that operate NMS Stock Alternative Trading Systems (off-exchange equity venues such as dark pools, midpoint crossing networks, and conditional order systems). The legal filer is the broker-dealer operator, registered under Section 15 of the Exchange Act and a member of FINRA, not the ATS itself.
Initial Form ATS-N is filed before a venue commences NMS-stock operations. Material amendments (ATS-N/MA) are filed at least 30 calendar days before implementing a material operational change. Updating amendments (ATS-N/UA) aggregate non-material changes within a calendar quarter and are due within 30 days of quarter-end. Correcting amendments (ATS-N/CA) are filed promptly when a prior filing is found to contain an inaccuracy.
The dataset begins with the earliest Form ATS-N filings on EDGAR in May 2019 (Form ATS-N became operative in early 2019 under the SEC's 2018 Regulation ATS-N rulemaking) and continues forward with monthly refreshes.
Each accession folder contains XML (the structured form and its XHTML rendering), JSON (the metadata.json wrapper), and PDF (exhibits such as Form BD Schedule A and Schedule B copies, and any attached safeguards and procedures documents). Image files are excluded, and the EDGAR-generated SGML "Complete submission text file" is referenced by URL but not stored on disk.
Form ATS-N is the public, narrative, structural disclosure for NMS Stock ATSs under Rule 304. Legacy Form ATS is the confidential registration filing for ATSs that do not trade NMS stocks (fixed income, options, municipal debt). Form ATS-R is the confidential quarterly volume report filed by all ATSs. ATS-N describes how a venue operates; ATS-R reports how much it traded; legacy ATS covers the non-equities side of the same venue universe.
Walk the filing chain for that ATS by CIK and form-type sequence from the initial ATS-N forward. Amendments (ATS-N/MA, ATS-N/UA, ATS-N/CA) often restate only the items being changed, so unchanged Items must be carried forward from the most recent prior filing. The deterministic <prefix>Part<N>Item<n>... element naming makes this diffable element-by-element across successive primary_doc.xml documents.