What are the limitations of 13F data?

13F filings are delayed (up to 45 days after quarter end), only cover long positions (not shorts, options, or non-US securities), and only apply to managers with $100M+ in qualifying assets.

How to Read SEC Form 13F Filings | PlainFundData Guide

Q: What is a Form 13F filing?

A Form 13F is a quarterly report filed with the SEC by institutional investment managers with at least $100 million in qualifying assets under management. It discloses long positions in US-listed securities.

Q: When are 13F filings due?

Form 13F filings are due within 45 days after the end of each calendar quarter. Q4 filings (December 31 period) are due by February 14.

What Is Form 13F?

SEC Form 13F is a quarterly filing required of institutional investment managers with at least $100 million in qualifying assets under management. The filing discloses the manager's long positions in publicly traded US equity securities as of the end of each calendar quarter.

These filings are public record and provide a window into what the largest institutional investors, hedge funds, mutual funds, pension funds, and investment advisors, are holding in their portfolios.

What Data Does 13F Include?

Security Name (Name of Issuer)

The company whose shares are held

CUSIP Number

A unique 9-character identifier for the security

Share Count (sshPrnamt)

Number of shares or principal amount held

Market Value

Reported market value of the position at quarter end

Investment Discretion

Whether the manager has sole, shared, or defined discretion

Voting Authority

Whether the manager has sole, shared, or no voting authority

Put/Call Indicator

For options positions, whether put or call options

Key Limitations to Understand

⏰ 45-Day Delay

Filings are due 45 days after quarter end. By the time you see the data, positions may have changed significantly.

📉 Long Positions Only

13F only covers long equity positions. Short positions, bonds, derivatives (except certain options), and foreign securities are not required to be disclosed.

💰 $100M Threshold

Only managers with $100M+ in qualifying assets must file. Smaller funds are invisible in this data.

🔢 Aggregated Positions

Multiple accounts managed by one firm are aggregated. A single 13F may represent hundreds of underlying client accounts.

🌍 US Securities Only

Only securities listed on US exchanges (or convertibles and certain warrants) are required to be reported.

See it in the data

The same 13F filings power every page on this site. Here are the stocks the most institutions currently report holding, open any name to see who owns it.

1

MICROSOFT CORP 44 holders

$1.9B reported
2

ALPHABET INC 43 holders

$954.1M reported
3

APPLE INC 42 holders

$1.4B reported
4

NVIDIA CORPORATION 40 holders

$2.2B reported
5

AMAZON COM INC 39 holders

$1.1B reported
6

SPDR S&P 500 ETF TR 36 holders

$276.2M reported

Most widely held US stocks by number of reporting institutions

FAQ

When are 13F filings due?

Within 45 calendar days after the end of each quarter. Q1 (March 31) → due by May 15. Q2 (June 30) → due by August 14. Q3 (September 30) → due by November 14. Q4 (December 31) → due by February 14.

Who must file Form 13F?

Institutional investment managers that exercise investment discretion over $100 million or more in Section 13(f) securities. This includes mutual funds, hedge funds, pension funds, banks, insurance companies, and investment advisors.

Can I use 13F data for investment decisions?

Institutional ownership data can be one signal among many, but it has significant limitations (45-day delay, no shorts disclosed, aggregated data). Always consult a licensed financial advisor before making investment decisions.

Common misreadings to avoid

A 13F is easy to over-interpret. The most frequent mistake is treating the filing as a live portfolio: by the time it is public, the quarter it covers is already two to four months old, and an active manager may have entered or exited positions you will never see until the next quarter. Read every figure as "what was held at the close of the reporting quarter", not "what is held today".

A second trap is reading a manager's reported value as its assets under management. 13F captures long US-listed equity positions only, it omits short positions, cash, bonds, commodities, non-US equities and most derivatives. A fund with a $50 billion reported 13F book may run several times that across asset classes the form never touches, so "13F value" measures the size of a manager's disclosed long-equity sleeve, nothing more.

Third, a single new position is rarely a signal on its own. Index funds and quantitative managers rebalance mechanically, so a "new buy" can simply reflect a benchmark change rather than conviction. Look for the same move across several unrelated managers, weigh it against the position's size relative to the fund's book, and remember that confidential-treatment requests let some managers delay disclosing newly-initiated positions entirely. Used carefully, as one input among many, never as a stand-alone trade trigger, 13F data is a useful window into institutional positioning; used literally, it misleads. Cross-check anything that matters against the original filing on SEC EDGAR before acting on it.

Not investment advice: PlainFundData presents SEC 13F data for informational purposes only. This is not investment advice. Always consult a licensed financial advisor.

About this guide's sources

Every figure and example in this guide traces back to SEC Form 13F-HR filings in the U.S. Securities and Exchange Commission's EDGAR system, the public record of long US-listed equity positions held by institutional managers with at least $100 million in qualifying assets. PlainFundData standardizes those filings so they are easier to read; where we cite a number, it is rendered from the filing data, not estimated. Form 13F is a quarter-old, long-only snapshot, so its limitations are noted throughout rather than implying a complete or real-time view of any manager's holdings.