Methodology & Data Sources

Editorial Workflow

Content on PlainFundData is compiled by our editorial team from official source filings and reviewed before publication. Raw filings from SEC EDGAR (13F-HR, N-CEN, N-PORT) are ingested programmatically by our ETL pipeline; narrative framing, guide text, rankings commentary, and methodology writeups are drafted by the PlainFundData Editorial team at Kiznis Studio and reviewed line-by-line against the source before publication. No page on PlainFundData is published without editorial review. We do not accept payment for coverage, placement, or rankings — "top holders", "largest positions", and all rankings are computed directly from SEC filings.

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. 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.

Coverage

PlainFundData tracks holdings for 5,000+ institutional funds across 8,000+ securities, with quarterly snapshots enabling quarter-over-quarter change tracking. 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.
• 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.

Contact

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