Methodology & Data Sources

Editorial Workflow

Content on PlainFundData is compiled by our editorial process from official source filings and reviewed before publication. Every number on this site traces back to a raw SEC EDGAR Form 13F-HR filing, pulled directly from the source with no manual re-entry. The prose around that data, narrative framing, guide copy, rankings commentary, methodology explanations, is a different matter: our editors draft it, check it against the underlying filings, and sign off before it goes live. That editorial pass covers the templates and the written guides, not each individually generated fund or stock page; with thousands of those pages compiled from the same filing corpus, claiming a human read every single one would overstate what actually happens here, so we don't. Nothing on PlainFundData runs without that editorial sign-off, and none of it is for sale: "top holders," "largest positions," and every other ranking are pure arithmetic on the SEC's own numbers, not a placement anyone pays for.

Data Source

All data on PlainFundData comes directly from SEC EDGAR Form 13F filings. Under Section 13(f) of the Securities Exchange Act of 1934, institutional investment managers with $100 million or more in qualifying assets under management are required to disclose their long equity positions to the Securities and Exchange Commission within 45 days of each calendar quarter end. These filings are public domain U.S. government data available through the SEC EDGAR system, and the SEC publishes its own Form 13F FAQ explaining the filing requirement. Form 13F is the primary mechanism through which the public can monitor how the largest institutional investors, hedge funds, mutual funds, pension funds, insurance companies, and endowments, allocate capital across the equity market.

Corpus Placement

Every fund and stock detail page leads with an according-to corpus ordinal (where that entity sits in PlainFundData's published set) so the page answers a placement question the raw SEC filing does not.

• Funds: rank among filers with reported book value > 0, ordered by reported 13F equity value descending (ties broken by slug). This matches the /funds listing and the funds sitemap.
• Stocks: rank among securities with ≥5 reporting holders, ordered by aggregate reported institutional value descending (ties broken by slug). This matches the stocks sitemap filter and the value sort used on /stocks for indexable names. Separate holder-breadth ranks on stock pages use the broadly-held (≥10 holders) peer set and are labeled as such; they are complementary, not the listing-matched LEAD.

Ordinals are recomputed live from the database (cached per process for stability under a single worker). Percentile gauges and concentration dials elsewhere on the page remain complementary; the binding placement signal is the listing-matched #N of M.

Coverage

The SEC receives Form 13F filings from over 5,000 institutional investment managers each calendar quarter. PlainFundData currently tracks holdings for 360+ institutional funds across 7,700+ securities, with quarterly snapshots enabling quarter-over-quarter change tracking, and this coverage is expanding over time. The dataset includes hedge funds, mutual fund complexes, pension fund managers, insurance companies, university endowments, family offices above the reporting threshold, and registered investment advisors. Securities covered include common stock, American Depositary Receipts (ADRs), ETFs, closed-end funds, and certain convertible securities that appear on the SEC's official 13F securities list.

Processing Pipeline

1. Form 13F XML filings are downloaded from SEC EDGAR for each reporting quarter. Both primary filings and amendments (13F-HR/A) are collected, with amendments superseding the original filing for the same quarter.
2. Holding tables within each filing are parsed to extract CUSIP identifiers, issuer names, share class designations, market value in thousands of dollars, total shares or principal amount held, and investment discretion type (sole, shared, or defined).
3. CUSIPs are mapped to ticker symbols and standardized company names using the SEC's official 13F securities list and supplementary CUSIP-to-ticker reference tables, resolving corporate actions such as ticker changes, mergers, and spin-offs.
4. Quarter-over-quarter changes are computed for every fund-security pair: shares added, shares reduced, new positions initiated, and positions completely sold. Market value changes are also tracked, distinguishing between changes due to trading activity and changes due to price movement.
5. Ownership concentration metrics are calculated from the security side: identifying the top institutional holders by value, new large positions, exits by major holders, and aggregate institutional ownership as a percentage of shares outstanding where float data is available.
6. Fund-level portfolio analytics are computed: total portfolio value, number of holdings, portfolio concentration (top-10 weight), sector allocation, and quarter-over-quarter turnover rate.
7. All data is loaded into a structured SQLite database indexed by fund CIK, security CUSIP, and filing quarter for fast lookup across fund profiles, security ownership pages, and quarter-over-quarter change reports.

Data Currency and Update Frequency

13F filings are due 45 days after each calendar quarter ends, May 15, August 14, November 14, and February 14. Most large funds file within the first two weeks of the deadline. PlainFundData processes new filings as they appear on EDGAR, with the database typically refreshed within days of the filing deadline. Late filers and amendments are incorporated in subsequent processing runs. The quarterly reporting cadence means the most recent data reflects positions held at the end of the previous quarter, not current holdings.

Accuracy Commitment

PlainFundData reproduces SEC EDGAR filing data exactly as submitted by institutional managers. Share counts, market values, and position changes are calculated directly from the reported holdings without editorial modification. When a fund files an amendment that supersedes an earlier filing for the same quarter, the amendment data replaces the original. CUSIP-to-ticker mappings are validated against the SEC's official 13F securities list.

Limitations

• 13F filings report long equity positions only, short positions, most options, fixed income, commodities, foreign-only securities, and private placements are not required disclosures and do not appear in the data.
• Data is up to 45 days old when first published, and fund positions may have changed significantly by the time filings become available. Institutions frequently trade in and out of positions within a quarter.
• Managers may request confidential treatment for certain holdings under SEC Rule 13F-1(b), temporarily excluding those positions from public filings until the confidential treatment period expires.
• CUSIP-to-ticker mapping may occasionally be incorrect for OTC securities, foreign issuers, recently renamed companies, or securities that have undergone complex corporate actions.
• PlainFundData currently ingests a subset of all SEC 13F filers (360+ of the 5,000+ managers who file each quarter), not the complete universe. This subset is not yet curated by fund size, so "top holder" and ranking pages reflect only the funds currently in our database and may not include every large institutional holder of a given security. We are expanding coverage over time.
• This data is for informational purposes only and does not constitute investment advice. Past institutional holdings are not predictive of future performance or investment decisions.

Frequently Asked Questions

Not Affiliated

PlainFundData is not affiliated with the U.S. Securities and Exchange Commission, any fund issuer, any investment advisor, or any government agency. This site is for informational purposes only and does not provide investment advice.

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