// DATA COVERAGE
The data behind the research.
Sapinover runs on four datasets: a proprietary overnight tape collected from three ATSs every session, the full FINRA transparency record held at the security level, the complete SEC Form ATS-N corpus parsed into structured venue features, and an ETF layer built from N-PORT and N-CEN. Here is exactly what we hold, how far back it runs, and how often it refreshes.
Figures computed from the live datasets on August 5, 2026. Not estimates.
THE DATASETS
Overnight ATS Tape
PROPRIETARYProprietary, collected daily from three venues
Session-level overnight trading across Blue Ocean, Bruce Markets and Moon ATS, enriched with prior close, next open and next close so every session can be measured against the regular-hours market that follows it. This is the dataset no vendor sells.
September 2, 2025 to August 4, 2026
Every trading session, plus a post-close enrichment pass
FINRA ATS Transparency
FINRA Rule 4552, security-level weekly record
Weekly shares and notional for every NMS-equity ATS, held at the security level rather than as published summaries. Venue league tables, tier splits and concentration measures are computed from this base, which means any rank we publish is reproducible from the underlying rows.
Week of December 15, 2025 to week of July 6, 2026
Weekly, Friday, with back-fill as FINRA publishes Tier 2
SEC Form ATS-N Corpus
SEC EDGAR, complete filing history
Every Form ATS-N filing on record, parsed into structured venue features and diffed filing over filing so a change in how a pool matches, who it admits, or when it opens is captured as a discrete event rather than buried in a redline.
May 10, 2019 to July 31, 2026
Daily monitor against EDGAR
ETF Intelligence Layer
SEC N-PORT and N-CEN, cross-referenced with the overnight tape
Fund-level reference data, quarterly portfolio holdings, and annual fund-structure disclosures, joined to overnight trading activity. The holdings and structure layers come from filings most data vendors leave unparsed.
N-PORT 2026 Q1; N-CEN across four quarters to 2026 Q1
Quarterly for filings, monthly for reference data
HOW WE HANDLE IT
Primary sources only
Every figure traces to a regulatory filing or an exchange-reported record. Where a claim about a venue cannot be tied to its Form ATS-N, it does not get published.
Security-level, not summary-level
We hold the granular record and aggregate from it. That is why a venue rank can be recomputed, and why shares and notional can disagree without either being wrong.
Verified before publication
Counts in our research are reconciled against the source before a report ships, including a direct check against the SEC submissions record for filing counts.
Corrections are made in public
When a published figure turns out to be wrong, the page is corrected and the change is noted rather than quietly overwritten.
DATA PARTNERSHIPS
Need a cut we do not publish?
We run custom analysis against these datasets for venues, issuers and institutional desks: venue-level distribution studies, peer benchmarking, overnight flow attribution, and filing-driven monitoring. If there is a question the public research does not answer, tell us what you are trying to see.
ALPHA@SAPINOVER.COM