The Form ATS-N-W Files Dataset is the SEC EDGAR corpus of withdrawal notices filed by broker-dealer operators of NMS Stock Alternative Trading Systems under Rule 304 of Regulation ATS. One record represents one Form ATS-N-W submission — a single accession number capturing the moment a broker-dealer pulled an initial Form ATS-N, or a material amendment to an effective Form ATS-N, back from Commission review before it was declared effective or ineffective. Every filer is a registered broker-dealer that operates, or proposes to operate, an NMS Stock ATS, and every filing is a procedural pointer document that names the prior pending submission being withdrawn. The dataset is distributed as monthly ZIP containers nested in yearly folders, with each filing materialized as a folder containing the canonical XML submission, the EDGAR XHTML render, and a JSON header sidecar. Coverage begins with the earliest withdrawals on record in March 2021 and extends through the most recent monthly refresh.
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.
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Download a single container file (e.g. monthly archive) from the dataset.
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The dataset packages every Form ATS-N-W filed on EDGAR since the form's earliest in-corpus appearance in March 2021. Form ATS-N-W is the withdrawal counterpart to Form ATS-N within the Regulation ATS regime adopted in July 2018 (compliance date January 7, 2019), the rulemaking that subjected NMS Stock ATSs to a public Form ATS-N disclosure regime in lieu of the older confidential Form ATS treatment. Rule 304 obligates broker-dealer operators to file an initial Form ATS-N to operate, file material amendments before changing operations, and file updating amendments for non-material changes. Form ATS-N-W is filed only to withdraw an initial Form ATS-N or a previously submitted material amendment during the Commission's review period, before the SEC has declared the filing effective or ineffective. It is not a cessation-of-operations vehicle for an already-effective ATS — that runs through Form ATS-N cessation procedures.
Because its only substantive purpose is to point at a prior pending submission and remove it from review, Form ATS-N-W is intentionally minimal. It carries no operational disclosure, no order-handling description, no fee schedule, and no narrative — those live on the Form ATS-N being withdrawn. ATS-N-W functions as a short administrative pointer document referencing another EDGAR accession.
The dataset distributes records as ZIP containers using the file types XML (the canonical submission and its XHTML render, both stored with an .xml extension) and JSON (the header sidecar). There is no cross-filing rollup, no event-level extraction, and no normalized table — each record is a complete, self-contained representation of one ATS-N-W submission.
One record is exactly one EDGAR filing of Form ATS-N-W — a single withdrawal notice submitted by the broker-dealer operator of an NMS Stock Alternative Trading System under Rule 304 of Regulation ATS. The unit of observation is one accession number, materialized as a folder named with the undashed 18-digit accession identifier (for example 000095012325006807 or 000075383525000021) inside a monthly partition of a yearly ZIP. The folder bundles the canonical XML submission, the EDGAR-rendered XHTML view, and a JSON header sidecar.
The dataset partitions records into monthly ZIPs nested in yearly folders (e.g. 2025/2025-07.zip). Inside the ZIP, each filing occupies its own folder named with the undashed accession number, and each folder contains exactly three files:
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<YYYY-MM>/
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└── <accession-no-dashes>/
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├── metadata.json
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├── primary_doc.xml
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└── xslATS-N-W_X01/
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└── primary_doc.xml
There are no SGML wrappers (.txt complete-submission files), no HTML exhibits, no PDF attachments, and no image files. The complete-submission .txt is reachable via URL in the metadata but is not bundled.
The three files have distinct roles:
metadata.json — EDGAR header metadata: filer identity block, the accession number of the current ATS-N-W, filing and effectiveness timestamps, a manifest of documents in the original EDGAR submission, and back-links to SEC.gov resources.primary_doc.xml — the canonical Form ATS-N-W instance document in the http://www.sec.gov/edgar/atsncw namespace. Structured, machine-readable form data.xslATS-N-W_X01/primary_doc.xml — an XHTML 1.0 Strict rendering of the same form, the human-readable view EDGAR serves on the filing detail page. Despite the directory name, the file is XHTML, not XSLT; the directory simply mirrors EDGAR's URL path for the rendered view.metadata.jsonA flat JSON object describing the ATS-N-W submission at the EDGAR-header level:
formType — fixed string "ATS-N-W".accessionNo — dashed accession of the current ATS-N-W submission (e.g. "0000950123-25-006807").effectivenessDate — ISO date EDGAR records the filing as effective.filedAt — ISO datetime with timezone offset for acceptance.description — fixed boilerplate "Form ATS-N-W - Withdrawal of Form ATS-N Filing (Form ATS-N Instruction No. 9)".linkToFilingDetails — URL to the rendered XHTML view on SEC.gov.linkToTxt — URL to the SGML complete-submission .txt on EDGAR (the .txt is not bundled into the ZIP).linkToHtml — URL to the EDGAR filing index page for the accession.linkToXbrl — empty string.documentFormatFiles[] — manifest enumerating the submission documents on EDGAR (the XSL-rendered XML, the canonical primary_doc.xml, and the complete-submission .txt). Each entry reports a sequence number, document URL, type, and size in bytes; size is occasionally reported as a single-space string when EDGAR did not stamp a value.entities[] — single-element array describing the filer with companyName (suffixed "(Filer)", e.g. "GOLDMAN SACHS & CO. LLC (Filer)", "BNP PARIBAS SECURITIES CORP. (Filer)"), cik (unpadded), fileNo (the 013- broker-dealer file number), irsNo, stateOfIncorporation, fiscalYearEnd, act ("34" for the Exchange Act), type ("ATS-N-W"), and filmNo.id — 32-character hex content hash assigned by the dataset publisher.seriesAndClassesContractsInformation — empty array; the concept does not apply to ATS-N-W.dataFiles — empty array; ATS-N-W has no associated data files.primary_doc.xml — canonical XMLThree namespaces are declared on the root:
xmlns="http://www.sec.gov/edgar/atsncw"xmlns:com="http://www.sec.gov/edgar/common"xmlns:ats="http://www.sec.gov/edgar/atsncommon"The element tree is fixed:
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<edgarSubmission>
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<headerData>
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<submissionType>ATS-N-W</submissionType>
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<accessionNumber>...</accessionNumber> <!-- accession of the ATS-N being WITHDRAWN -->
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<filerInfo>
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<liveTestFlag>LIVE</liveTestFlag>
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<filer>
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<filerCredentials>
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<com:cik>0000753835</com:cik> <!-- 10-digit zero-padded -->
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<com:ccc>XXXXXXXX</com:ccc> <!-- redacted -->
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</filerCredentials>
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<MPID>BNPX</MPID> <!-- Market Participant ID of the ATS -->
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<NMSStockATSName>BNPP Cortex </NMSStockATSName>
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</filer>
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<contact>
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<ats:contactName>...</ats:contactName>
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<ats:contactPhoneNumber>...</ats:contactPhoneNumber>
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<ats:contactEmailAddress>...</ats:contactEmailAddress>
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</contact>
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<flags>
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<ats:overrideInternetFlag>false</ats:overrideInternetFlag>
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<ats:confirmingCopyFlag>false</ats:confirmingCopyFlag>
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</flags>
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</filerInfo>
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</headerData>
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<formData>
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<!-- empty by design for ATS-N-W -->
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</formData>
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</edgarSubmission>
Substantive values are concentrated in a handful of fields:
headerData/submissionType — always ATS-N-W.headerData/accessionNumber — the accession of the prior Form ATS-N filing being withdrawn. The most important and most easily misread field in the form (see Interpretation notes below).filerInfo/liveTestFlag — LIVE for production filings, TEST for EDGAR test submissions.filer/filerCredentials/com:cik — the operator's CIK, zero-padded to 10 digits.filer/filerCredentials/com:ccc — the CIK Confirmation Code, always redacted as XXXXXXXX in the published instance.filer/MPID — the four-letter Market Participant ID of the NMS Stock ATS (e.g. SGMT for Sigma X2, BNPX for BNPP Cortex).filer/NMSStockATSName — the human-readable trade name of the ATS (e.g. Sigma X2, BNPP Cortex).contact/* — name, phone, and email of the EDGAR-filing contact for the operator.flags/* — overrideInternetFlag and confirmingCopyFlag, both typically false for live withdrawals.formData is present but intentionally empty: the form's regulatory design places no body fields under formData because the only substantive disclosure is the pointer to the withdrawn accession in the header.
xslATS-N-W_X01/primary_doc.xml — XHTML renderEDGAR's human-viewable rendering of the same form. An XHTML 1.0 Strict document linking /css/ATSN_print.css, opening with the standard OMB approval block (OMB number 3235-0763) and the SEC disclaimer beginning "THE SECURITIES AND EXCHANGE COMMISSION HAS NOT PASSED UPON THE MERITS...", then laying out the same fields as the canonical XML inside <div class="fakeBox"> form-mock widgets: Filer CIK, Filer CCC, MPID of the NMS Stock ATS, Name of NMS Stock ATS, Accession Number of Filing Withdrawn, contact name/phone/email, and LIVE/TEST radio selectors rendered as <img> tags. The render also reserves placeholder fakeBox containers for the form's Part IV (Contact Information, Signature Block, Consent to Service of Process); those containers are present in the rendered HTML but empty, because Instruction No. 9 of Form ATS-N does not require those parts to be completed when the purpose of the submission is withdrawal. The render carries no information beyond what the canonical XML and metadata already provide; it exists for visual fidelity with EDGAR.
This is the full set needed to identify the ATS, the operator, the contact, the date of withdrawal, and the accession number of the prior ATS-N being withdrawn.
.txt — the SGML wrapper is referenced via linkToTxt but is not stored in the ZIP. Consumers needing the original SGML packet must fetch it from EDGAR..jpg/.gif/.png payloads from the SEC submission are excluded by dataset policy. ATS-N-W filings rarely if ever carry images, but the policy is uniform across the corpus.primary_doc.xml/headerData/accessionNumber; the actual ATS-N content must be retrieved separately.Form ATS-N-W has been a structured XML form since inception. There is no ASCII/text era and no HTML-only era — the form was born after EDGAR's structured-XML modernization. The schema (http://www.sec.gov/edgar/atsncw) and the EDGAR rendering template (xslATS-N-W_X01) have been in continuous use since the form was operationalized in January 2019, and no material changes to required content have been issued since adoption. The substantive payload has remained: identity of the ATS and operator, MPID, contact information, LIVE/TEST flag, and the accession number of the filing being withdrawn.
primary_doc.xml/headerData/accessionNumber is not the accession of the current ATS-N-W submission — it is the accession of the prior Form ATS-N filing being withdrawn. To recover the current ATS-N-W's own accession, use metadata.json/accessionNo or the folder name. Worked examples: in the BNP Paribas BNPP Cortex withdrawal where the folder is 000075383525000021 and metadata.json/accessionNo is 0000753835-25-000021, the XML carries 0000753835-25-000020 (the ATS-N being withdrawn). In the Goldman Sachs Sigma X2 withdrawal in folder 000095012325006807, the XML carries 0000950123-25-006607 as the withdrawn ATS-N's accession against a current accession of 0000950123-25-006807. The withdrawn-filing accession is typically numerically earlier than the current one but separated by an arbitrary gap, not a fixed offset.0000042352); metadata.json/entities[].cik reports it unpadded (42352). Joins across the two representations must normalize.0000950123-25-006807, in metadata.json and URLs), undashed (000095012325006807, the folder name), and dashed inside the XML — where the value refers to the withdrawn filing rather than the current one.NMSStockATSName may appear as "BNPP Cortex " with a trailing space. Consumers building canonical names should normalize whitespace.formData is by design. Do not treat the empty element as a parsing or extraction error.com:ccc is always XXXXXXXX; the real CIK Confirmation Code is a private credential and is not present in the dataset.documentFormatFiles[] occasionally report size as a single-space string rather than an integer or null, particularly for the rendered XHTML. Treat size as opportunistic metadata..txt is not bundled. Reachable via linkToTxt on SEC.gov but not part of the record folder; SGML-dependent workflows must fetch it separately.MPID (four-letter Market Participant ID) and NMSStockATSName together are the most reliable identity keys for the ATS itself; cik, companyName, and fileNo identify the operating broker-dealer. A single broker-dealer can operate multiple NMS Stock ATSs, so MPID and ATS name should not be treated as derivable from CIK alone.Every Form ATS-N-W is filed by a registered broker-dealer that operates, or proposes to operate, an NMS Stock Alternative Trading System. To be in this filing population, the entity must:
The legal filer is always the broker-dealer operator, not the trading platform brand. The EDGAR filer CIK on a Form ATS-N-W is the broker-dealer's CIK; the ATS name appears inside the form. Operators include bank-affiliated dealers, independent agency brokers, and wholesale market makers, drawn from the roughly 30 to 35 NMS Stock ATSs registered at any given time.
ATSs that trade only non-NMS securities (corporate or municipal bonds, Treasuries, unlisted equity, private-company shares) are outside this population. They file under the legacy Form ATS / Form ATS-R / ATS-W regime in Rule 301(b)(2) and never generate Form ATS-N-W records. National securities exchanges, ECNs registered as exchanges, and broker-dealer internalizers that do not meet the Rule 3b-16 exchange definition are likewise excluded.
A Form ATS-N-W is filed at the broker-dealer operator's discretion to withdraw a Form ATS-N submission that is still under Commission review. There are two trigger contexts:
Common practical causes include adverse staff feedback during review, abandonment of the proposed venue or feature set, M&A or restructuring of the operator, rebranding that requires a fresh Form ATS-N, or exit from the NMS Stock ATS business. Where the operator still intends to proceed with revised disclosures, a Form ATS-N-W is typically followed by a refiled Form ATS-N that restarts the review clock.
Form ATS-N-W has no statutory deadline. It may be filed at any point while the underlying Form ATS-N or material amendment is pending — that is, after submission and before the Commission has either declared the form effective or issued a notice of ineffectiveness. Under Rule 304(a)(2), the review period is generally 120 calendar days for an initial Form ATS-N (extendable) and 30 calendar days for a material amendment (extendable up to 90 days); a withdrawal may be filed anywhere inside that window.
The withdrawal takes effect on filing. No Commission action, waiting period, or public-comment process is required. Once submitted, the underlying Form ATS-N or amendment is treated as withdrawn, the review clock terminates, and the ATS may not operate under the withdrawn filing. Refiling is permitted and starts a new review period; successive Form ATS-N / Form ATS-N-W cycles for the same venue are visible in EDGAR.
Because filings are voluntary and tied to specific pending submissions rather than periodic or transactional triggers, Form ATS-N-W records do not arrive on a regular cadence. They cluster around the small set of ATSs with pending Form ATS-N activity and around episodic events such as venue restructurings and acquisitions of broker-dealer operators.
Form ATS-N-W exists under Regulation ATS, codified at 17 CFR 242.300 through 242.304. The withdrawal mechanic is at Rule 304(a)(1)(iv), which governs the procedures for filing, amending, and withdrawing Form ATS-N. Regulation ATS draws its authority from Section 11A (national market system), Section 15 (broker-dealer regulation), and Section 19 (review procedures, including the Section 19(d) framework that informs Form ATS-N effectiveness/ineffectiveness determinations) of the Exchange Act.
Form ATS-N and Form ATS-N-W were created by the SEC's 2018 Regulation ATS-N rulemaking, which subjected NMS Stock ATSs to a public Form ATS-N disclosure regime in lieu of the older confidential Form ATS treatment. The compliance date for initial Form ATS-N filings was in 2019; Form ATS-N-W has only ever existed as an EDGAR-filed electronic record, with the earliest withdrawals in this dataset dating to March 2021.
Form ATS-N-W sits inside a tightly clustered family of Regulation ATS filings whose names, filers, and Rule 304 hooks overlap heavily. The single most important takeaway is this: ATS-N-W withdraws a pending filing, not an operating ATS. It pulls a Form ATS-N or material ATS-N/A back from Commission review before it becomes effective. It does not stop trading, retire an effective disclosure, or shut down a venue. Every comparison below should be read against that boundary.
The public, narrative-and-tabular operations disclosure that a broker-dealer files under Rule 304 to register an NMS Stock ATS (order types, subscribers, fees, conflicts, affiliates, market data use). ATS-N-W is the exit door for that filing while it remains under review. ATS-N-W references the accession number of the ATS-N being withdrawn and is meaningless without it.
Filed when an operating NMS Stock ATS materially changes its operations and triggers a fresh Commission review period. ATS-N-W is the withdrawal counterpart of these pending material amendments just as much as of initial ATS-N filings. Use Form ATS-N/A to track substantive operational changes; use ATS-N-W when the operator pulls one back before effectiveness.
Both are housekeeping: Form ATS-N/UA refreshes the disclosure on a non-material basis (often annual), and Form ATS-N/CA fixes errors or omissions in an already-filed ATS-N. Neither typically generates an ATS-N-W because there is no substantive review period to withdraw from. ATS-N-W does not correct or refresh content; it removes a pending document from the Commission's queue entirely.
This is the most common source of confusion, driven by the near-identical suffix. The distinction is unmistakable:
Different rules (301 vs. 304), different ATS populations (non-NMS vs. NMS Stock), and fundamentally different real-economy meaning: ATS-W means trading stops; ATS-N-W means a draft disclosure is shelved.
The confidential, non-public initial-operations report filed by non-NMS ATSs. Structural predecessor and parallel to Form ATS-N. ATS-N-W has no role here; withdrawals or cessations in the Form ATS regime flow through Form ATS-W or amendments to Form ATS.
A periodic, tabular volume-and-activity report under the original Form ATS regime. Operational and quantitative — not a substitute or analog for ATS-N-W's event-driven procedural withdrawal. The only kinship is the shared Regulation ATS umbrella.
Used by SROs (exchanges, FINRA, clearing agencies) to propose rule changes for Commission approval. Sometimes grouped mentally with ATS disclosures because both involve Commission review of venue rules. But 19b-4 covers SROs, not ATSs, and its withdrawal mechanism is internal to the 19b-4 process. ATS-N-W has no role at exchanges or other SROs.
The alternative path for a venue that opts to register as a national securities exchange (Section 6) or clearing agency rather than operate as an ATS. ATS-N-W is sometimes filed when an operator pivots toward the exchange path, but Form 1 / CA-1 are not ATS documents. Use them to track venues entering the exchange perimeter; use ATS-N-W to track which pending NMS Stock ATS disclosures were retracted — some of which may foreshadow a Form 1.
The Form ATS-N-W dataset is distinct because it covers exactly one narrow procedural event: a broker-dealer withdrawing a pending Form ATS-N or material ATS-N/A for an NMS Stock ATS during the Commission review period.
It is not:
ATS-N tells you what an NMS Stock ATS proposes or how it operates; ATS-N-W tells you which of those proposals never crossed the effectiveness line. Used together — ATS-N-W references the accession number of the underlying filing — the dataset functions as a procedural index of retracted NMS Stock ATS disclosures. No related dataset can substitute for it when the research question is which pending NMS Stock ATS filings were withdrawn before effectiveness, by whom, and when.
Each ATS-N-W filing marks a broker-dealer pulling a previously submitted Form ATS-N (initial dark-pool registration or material amendment) before SEC review concludes. The record is short but operationally significant, and a defined set of professionals consumes it for distinct workflows keyed on a few fields: filer CIK, MPID, ATS legal name, prior ATS-N accession number, withdrawal date, and stated reason.
Equity microstructure analysts maintain live inventories of pending, effective, and withdrawn NMS Stock ATSs. They join filer CIK, ATS name, and MPID against an internal venue master, then pull the withdrawn ATS-N accession to read the abandoned matching logic, order types, and conflicts disclosures. Outputs include venue-pipeline dashboards and periodic reports tracking entry rates, withdrawal rates, and median time from filing to withdrawal.
Regulatory counsel at firms operating or launching an NMS Stock ATS treat peer ATS-N-W filings as precedent. Before drafting their own ATS-N or material amendment, they study which prior submissions failed to survive review, the stated reason, the filing-to-withdrawal interval, and whether the operator refiled. The prior ATS-N accession, filer CIK, and reason field drive the workflow: cleaner submissions, anticipated staff comments, and better timing of material amendments.
Trading-and-markets and market regulation staff use the dataset for situational awareness over the venue pipeline and to correlate withdrawal clusters with rulemaking, no-action positions, or staff guidance. They focus on withdrawal date, operator identity (CIK, MPID), and reason text to calibrate review priorities and produce internal statistics on how the ATS-N regime is functioning.
Heads of trading, execution analysts, and venue committees at institutional asset managers and hedge funds run continuous venue due diligence. An ATS-N-W on a pending or soon-to-launch venue changes the routing roadmap: they reconcile the withdrawal against broker-published venue lists, update internal questionnaires and scorecards, and prompt follow-ups with executing brokers on whether the venue will refile. Key fields are ATS name, operator CIK, date, and reason.
Smart-order-router engineers and venue-connectivity product managers use ATS-N-W filings to maintain venue inventories. A withdrawn initial ATS-N lets them deprioritize FIX sessions, drop copies, market-data feeds, and onboarding work; a withdrawn amendment signals that planned counterparty routing-logic changes will not arrive. They key on MPID and operator CIK to adjust integration backlogs and TCA reference data.
Researchers studying dark-pool entry and exit, Reg ATS-N transparency, and SEC review dynamics use the dataset as a labeled population of withdrawal events. Typical work merges ATS-N, ATS-N-W, amendments, and quarterly ATS volume statistics into panels keyed on operator CIK and ATS name, then estimates hazard models for venue survival or tests whether the regime has shifted entry behavior. Withdrawal date, prior accession, operator identity, and reason text matter most.
Reporters covering equity market structure use the dataset to anchor stories on specific dark pools that have been launched, restructured, or shelved. The fields provide a primary-source trail: named operator, ATS brand name, withdrawal date, and a link back to the original ATS-N narrative. A single ATS-N-W often becomes the basis for an explanatory piece on why a venue concept was abandoned.
Lawyers and litigation consultants on ATS-related disclosure matters — private actions and enforcement around order handling, conflicts, or venue marketing — use ATS-N-W filings to reconstruct a venue's disclosure history. The prior ATS-N accession surfaces the no-longer-effective text the operator had proposed, which supports arguments about what was disclosed and when. Outputs are exhibits, expert reports, and document requests grounded in operator CIK, ATS name, prior accession, withdrawal date, and reason.
Vendors publishing NMS ATS reference data (venue IDs, MPIDs, operator hierarchies, lifecycle status flags) rely on ATS-N-W filings to keep the "pending" subset accurate. Data engineers ingest the metadata (accession, filer CIK, filing date, form type) and link the withdrawal to the prior ATS-N so downstream clients see correct lifecycle state in delta files.
Across all of them, the same fields — operator CIK and name, ATS legal name, MPID, withdrawal date, prior ATS-N accession, and reason — drive the work.
Form ATS-N-W records are short, but each one is a clean procedural signal — a broker-dealer pulling a pending NMS Stock ATS disclosure back from SEC review. The use cases below all turn on the same handful of fields: filer CIK, MPID, NMS Stock ATS name, the prior Form ATS-N accession number, and the withdrawal date.
Reference-data engineers join ATS-N-W records to ATS-N filings on filer CIK + prior accession number and use the withdrawal date to flip the lifecycle status of the underlying ATS-N from pending to withdrawn. The output is a delta-ready feed of the live NMS Stock ATS universe (MPID, ATS name, operator CIK, status) that downstream clients consume to keep venue masters accurate.
A smart-order-router engineer ingests new ATS-N-W folders monthly, keys on MPID and operator CIK, and removes or deprioritizes any venue whose initial Form ATS-N has been withdrawn. The same workflow flags withdrawn material amendments so planned counterparty routing-logic changes are pulled from the integration backlog before FIX sessions, drop copies, and market-data subscriptions are stood up.
A buy-side execution analyst runs a daily diff of new ATS-N-W filings against the venue list their executing brokers route to. When the NMS Stock ATS name or MPID matches a venue on the planned routing roadmap, the system fires an alert that triggers a follow-up with the broker, an update to the venue scorecard, and a hold on any pending onboarding questionnaire.
ATS regulatory counsel at a broker-dealer preparing a new Form ATS-N or material amendment pulls every ATS-N-W from the last several years, retrieves the prior ATS-N accession from headerData/accessionNumber, and reads the abandoned disclosures alongside the time gap between filing and withdrawal. The result is a peer-precedent file that informs draft language, anticipated staff comments, and submission timing.
Microstructure researchers build a panel keyed on operator CIK and prior ATS-N accession, with the ATS-N filing date as entry and the ATS-N-W filedAt as the failure event. They fit a hazard model of how often pending NMS Stock ATS filings get withdrawn, conditional on operator type, MPID, and calendar period — directly testing whether Reg ATS-N has shifted dark-pool entry dynamics since 2019.
Market structure analysts isolate ATS-N-W records whose withdrawn accession resolves to an initial Form ATS-N (rather than a material amendment) and filedAt falls after March 2021. The resulting list — operator name, ATS name, MPID, withdrawal date — feeds quarterly venue-pipeline dashboards and underpins reports on how many would-be NMS Stock ATSs never crossed effectiveness.
Plaintiffs' counsel in an order-handling or conflicts case uses ATS-N-W to surface the prior, never-effective ATS-N a venue had proposed. The chain — current ATS-N-W folder, metadata.json/accessionNo, headerData/accessionNumber of the withdrawn ATS-N, operator CIK and ATS name — yields exhibits showing exactly what the operator put before the Commission, when it was pulled, and how it differs from any later refiling.
The Form ATS-N-W Files Dataset is available through three access methods: a JSON index API for programmatic discovery, a full archive download, and per-container downloads for selective retrieval.
Dataset Index JSON API: https://api.sec-api.io/datasets/form-atsnw-files.json
This endpoint returns dataset metadata (name, description, earliest sample date of 2021-03-01, total records, total size, supported form types, container format, and file types) along with the list of all available container files. Each container entry includes its key, size, record count, last update timestamp, and direct download URL. Use this endpoint to monitor which containers were updated in the most recent refresh and decide which ones to download. No API key is required to call this endpoint.
Example response:
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{
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"datasetId": "1f13365b-9ae0-6a6c-aa97-b529d9f1d4d0",
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"datasetDownloadUrl": "https://api.sec-api.io/datasets/form-atsnw-files.zip",
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"name": "Form ATS-N-W Files Dataset",
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"updatedAt": "2026-05-07T02:51:19.000Z",
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"earliestSampleDate": "2021-03-01",
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"totalRecords": 24,
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"totalSize": 46807,
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"formTypes": ["ATS-N-W"],
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"containerFormat": "ZIP",
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"fileTypes": ["XML", "JSON"],
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"containers": [
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{
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"downloadUrl": "https://api.sec-api.io/datasets/form-atsnw-files/2021/2021-03.zip",
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"key": "2021/2021-03.zip",
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"size": 8421,
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"records": 3,
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"updatedAt": "2021-03-15T14:22:00.000Z"
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}
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]
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}
Download Entire Dataset: https://api.sec-api.io/datasets/form-atsnw-files.zip?token=YOUR_API_KEY
Downloads the complete dataset as a single ZIP archive containing every Form ATS-N-W filing from March 2021 onward. This endpoint requires a valid API key passed via the token query parameter. Example with curl:
curl -o form-atsnw-files.zip "https://api.sec-api.io/datasets/form-atsnw-files.zip?token=YOUR_API_KEY"
Download Single Container: https://api.sec-api.io/datasets/form-atsnw-files/2021/2021-03.zip?token=YOUR_API_KEY
Downloads one individual monthly container instead of the full archive. Container paths follow the YYYY/YYYY-MM.zip pattern and can be discovered via the dataset index JSON API. This endpoint also requires a valid API key.
The dataset covers Form ATS-N-W, the withdrawal notice filed under Rule 304 of Regulation ATS by broker-dealer operators of NMS Stock Alternative Trading Systems. It is filed only to withdraw an initial Form ATS-N or a material amendment that is still pending before the Commission's review period.
One record is a single EDGAR Form ATS-N-W filing, materialized as a folder named with the undashed 18-digit accession number. The folder bundles the canonical XML submission (primary_doc.xml), the EDGAR XHTML render (xslATS-N-W_X01/primary_doc.xml), and a JSON header sidecar (metadata.json).
Only registered broker-dealers that operate, or propose to operate, an NMS Stock ATS — and that have an initial Form ATS-N or a material amendment currently pending before the Commission — file Form ATS-N-W. Non-NMS ATSs (corporate debt, municipal, Treasury, and other fixed-income venues), national securities exchanges, and ECNs registered as exchanges do not file this form.
Form ATS-W is the legacy cessation-of-operations form filed under Rule 301(b)(2)(iii) by ATSs in the older Form ATS regime when they shut down or change status, and it applies to non-NMS venues. Form ATS-N-W is filed under Rule 304 only to withdraw a pending Form ATS-N or material amendment for an NMS Stock ATS during Commission review — the venue itself typically continues to operate under any previously effective disclosure.
The single most important field is the accession number of the prior Form ATS-N being withdrawn, found at primary_doc.xml/headerData/accessionNumber. The common pitfall is reading this as the current ATS-N-W's own accession — it is not. To recover the current submission's own accession, use metadata.json/accessionNo or the folder name.
The earliest withdrawals in the corpus date to March 2021, with coverage continuing through the most recent monthly refresh. Records are distributed as monthly ZIP containers nested in yearly folders (YYYY/YYYY-MM.zip), and the bundled file types are XML (canonical submission and XHTML render) and JSON (header sidecar).
Form ATS-N-W has no statutory deadline and filings are voluntary, tied to specific pending Form ATS-N submissions. Records do not arrive on a regular cadence; they cluster around the small set of NMS Stock ATSs with pending Form ATS-N activity and around episodic events such as venue restructurings or operator acquisitions.