Investment Research Guides
Plain-language guides to understanding institutional ownership data, SEC 13F filings, and how to use this information in your investment research. Data from SEC EDGAR filings (13F-HR, N-CEN, N-PORT) by institutional managers with over $100 million in assets; see our methodology.
These guides are for educational purposes only and do not constitute investment advice. Always consult a licensed financial advisor.
How to Read SEC Form 13F Filings
A complete guide to understanding SEC Form 13F — what it reports, who files it, what the fields mean, and how to interpret quarterly changes.
What Institutional Ownership Means for Stocks
Why institutional ownership concentration matters, how it affects stock volatility and liquidity, and what high vs low institutional ownership signals.
Smart Money Signals: Following Institutional Investors
How to use 13F data to identify institutional buying and selling patterns. What the research says about following smart money — and its limitations.
13F Filing Deadlines and Reporting Calendar
SEC 13F quarterly filing deadlines, when data becomes available, how to track the filing cycle, and why timing matters for interpreting holdings data.
Understanding Ownership Concentration Scores
How PlainFundData calculates concentration scores, what high and low concentration means for a security, and how to use this metric in research.
Top Institutional Investors: Types and Strategies
Understanding the different types of institutional investors — hedge funds, mutual funds, pension funds, endowments — and how their 13F filings differ.
Limitations of 13F Data: What Filings Do Not Tell You
Critical limitations every investor should understand: delayed reporting, missing short positions, confidential treatment, and the backward-looking nature of 13F data.
Explore the Data Directly
Guides provide context. For the raw institutional ownership data, explore funds and stocks.
Methodology
Our guides are based on publicly available data from authoritative government sources. All statistics, ratings, and figures cited in these guides are drawn directly from official datasets and publications, with sources clearly referenced throughout.
We aim to present complex government data in plain language that is accessible to general audiences. When methodologies differ between data sources or change over time, we note these variations inline. Our editorial process includes regular reviews to ensure accuracy and timeliness of the information presented.