How do you read a 13F filing?
A Form 13F is the quarterly list of long US equity positions that an institutional investment manager files with the SEC once it manages $100 million or more in 13(f) securities. In 2026 it is due within 45 days of each quarter end (SEC Form 13F FAQ). Read the cover page, then the information table, then compare quarters.
What is a 13F filing?
A 13F is a snapshot of what a manager held on the last day of a quarter. Rule 13f-1 requires it from every institutional investment manager whose 13(f) securities had an aggregate fair market value of at least $100,000,000 on the last trading day of any month of a calendar year (17 CFR 240.13f-1, eCFR). Banks, bank holding companies and broker-dealers file too, alongside hedge funds and asset managers (SEC Form 13F FAQ).
The threshold has stayed at $100 million for decades. In 2020 the SEC proposed raising it to $3.5 billion (SEC proposing release 34-89290, 2020), but the rule text on eCFR still reads $100,000,000 in October 2026. Confirm the current figure on sec.gov before you rely on it.
Step 1. Find the filing on EDGAR
Search the manager's name in SEC EDGAR company search and filter the form type to 13F. Holdings reports appear as 13F-HR and amendments as 13F-HR/A. Open the most recent report and the one before it, because a single quarter tells you little on its own.
A manager's legal name often differs from its brand. If the search returns several entities, pick the one that files 13F-HR every quarter.
Step 2. Check the cover page and summary page
The cover page gives the reporting period, the filer and whether the filing is an amendment. The summary page gives the number of holdings and the total value, and lists any other managers included in the report.
Note the reporting period first. A filing made in mid-May describes positions held on 31 March, so it can be up to 45 days old on the day it appears.
Step 3. Read the information table
The information table is the list of positions. The SEC's instructions set the columns (SEC Form 13F instructions):
| Column | What it shows | What to look for |
|---|---|---|
| Name of issuer and title of class | The company and the share class | Match the name to the 13F List; watch for several classes of one company |
| CUSIP (and FIGI on newer filings) | The security identifier | Use it to join holdings across quarters and managers |
| Value | Market value at quarter end | Rank positions by size to see where the manager concentrates |
| Shares or principal amount | Number of shares held | Compare shares, not value, between quarters; price moves change value on their own |
| Put or call | Whether the line is an option | A call or put line is an option position, not stock |
| Investment discretion and other managers | Sole, shared or defined discretion | Shared discretion can mean an affiliate made the call |
| Voting authority | Sole, shared or none | Who votes the shares at meetings |
Step 4. Compare with the previous quarter
Line up the two information tables by CUSIP and sort each position into new, added, reduced, exited or unchanged. Use share counts, because value changes with the stock price even when the manager did nothing.
Most investing guides and forum threads make the same point: the change across several quarters says more than any one snapshot. A position that grows for 4 quarters running tells you more than a new line that may already have been sold.
Step 5. Adjust for what the 13F leaves out
A 13F covers only part of a manager's book. SEC staff say managers should not report short positions and should not net a short against a long in the same security; written puts and calls are not reported either (SEC Form 13F FAQ).
Only securities on the SEC's Official List of Section 13(f) Securities are reported. Foreign shares appear only when they trade on a US exchange or Nasdaq, and unsponsored pink sheet ADRs are excluded (SEC Form 13F FAQ). Cash, bonds outside the list, private holdings and most non-US securities do not show.
Some positions can be held back. Section 13(f)(4) of the Exchange Act lets the SEC delay or withhold public release, and open risk arbitrage positions can receive confidential treatment (SEC Form 13F FAQ). A later amendment may reveal them.
Is a 13F worth following?
It depends on the manager's strategy. A long-biased equity fund shows most of its exposure in a 13F, while a short-biased fund shows mainly its hedges, which can mislead (Market Folly, 2012). Investing forums return to 2 objections: the 45-day lag and the hidden short book. The common answer is to use 13F overlap as a prompt for your own research, never as a buy signal.
13F data is most useful for questions about ownership. Who are the largest institutional holders of a company, which managers entered this quarter, and how concentrated is the shareholder base? For a full picture of a company's owners, combine 13F with Schedule 13D and 13G filings, as set out in how to find who owns a company. To research the manager behind a 13F, read its registration form, explained in how to read Form ADV.
Where does Tamarly Intelligence help?
Tamarly Intelligence is Tamarly's research platform on companies, funds, countries and markets, built from official filings and open data. It reads 13F filings from SEC EDGAR and shows institutional holders on company pages, across 19,910 company pages. It also covers 2,888 funds, with holdings for 1,290 of them, and 15,359 fund managers from SEC filings. Every figure links to the filing it came from.
Tamarly shows no market prices and has no trading tools, so it will not chart a position's return. It also does not offer an Excel data feed of raw 13F tables. If you want to pull filings yourself, see free SEC filing search tools.
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Frequently asked questions
When are 13F filings due?
Within 45 days of the end of each calendar quarter (SEC Form 13F FAQ). A manager that first crosses $100 million files its first report for the December quarter of that year, then every quarter after it.
Does a 13F show short positions?
No. SEC staff say short positions are not reported and are not netted against long positions in the same security (SEC Form 13F FAQ). A 13F also leaves out cash and securities that are not on the SEC's Official List of Section 13(f) Securities.
Who has to file a 13F?
Any institutional investment manager that exercises investment discretion over 13(f) securities worth at least $100,000,000 on the last trading day of any month in a calendar year (17 CFR 240.13f-1). That includes hedge funds and asset managers as well as banks, bank holding companies and broker-dealers.
About the author. Melvine Manchau is the founder of Tamarly and author of the Tamarly Newsletter. He previously worked at PwC, Salesforce, BlackRock/eFront and Lazard.
About Tamarly Research. Tamarly Research is part of Tamarly Media, which holds no investment positions. Tamarly is a New York research house that studies how AI is changing regulated institutions.