What Is a 13F Filing? How to See What Famous Investors Own

Short answer: a 13F filing is a list of the US stocks a big investor owned on the last day of a quarter. Any money manager with $100 million or more in US-listed stocks must file one with the SEC, the US market regulator¹. It is due 45 days after each quarter ends². It is free to read on the SEC's website. But it is old news by the time you see it. It also leaves out short bets, cash, bonds and most foreign stocks. Use it as a list of ideas, not a shopping list.

So, what is a 13F filing in practice? It is the closest thing you get to looking over Warren Buffett's shoulder. Hedge funds, pension funds and famous stock pickers all file one. The next batch is due in mid-November 2026, covering what they held on September 30.

Below: who files, the exact deadline for every quarter through 2027, and what a 13F filing hides. Then we read a real one: Berkshire Hathaway's filing for the quarter that ended June 30, 2026.

What is a 13F filing, in plain English?

A 13F is a form. The name comes from Section 13(f) of the Securities Exchange Act of 1934, the law that created it³. Congress added that section in 1975. The goal was simple: let the public see what the biggest investors own.

Think of it as a photo of a shopping cart on one day. It shows what was inside. It does not show when each item went in, or what is in the cart today.

Each 13F filing has two parts:

• A cover page. Who filed it, which quarter it covers, and who signed it.
• An information table. One row per holding. Each row lists the company, its CUSIP (a 9-character ID code for a security), the number of shares, and the value in dollars on the last trading day of the quarter².

Since January 3, 2023, values are shown in whole dollars. Before that, they were in thousands of dollars¹. Keep that in mind if you compare an old filing with a new one.

Who has to file a 13F

The rule covers any "institutional investment manager." That is legal-speak for a firm or person that decides how to invest money, its own or other people's. Hedge funds, mutual fund firms, banks, insurers and pension funds all count.

A manager must file if it has investment discretion (the power to decide what to buy and sell) over at least $100 million of "13(f) securities"². The test is met if the total hits $100 million on the last trading day of any month in a year².

What counts toward the $100 million? Mostly stocks listed on US exchanges, plus some ETFs, listed options and convertible bonds. The SEC publishes the exact list every quarter, called the Official List of Section 13(f) Securities⁴.

Once a manager crosses the line, it files for that December quarter. It then files for the next three quarters too, even if its holdings fall back below $100 million¹.

13F filing deadline: every date for 2026 and 2027

The rule says 45 days after the end of each calendar quarter². If day 45 lands on a Saturday, Sunday or federal holiday, the filing is due the next business day¹. That small rule moves most of the deadlines below.

Quarter ends	Day 45	Actual 13F filing deadline
Dec 31, 2025 (Q4 2025)	Sat, Feb 14, 2026	Tue, Feb 17, 2026 (Mon Feb 16 was Presidents' Day)
Mar 31, 2026 (Q1 2026)	Fri, May 15, 2026	Fri, May 15, 2026
Jun 30, 2026 (Q2 2026)	Fri, Aug 14, 2026	Fri, Aug 14, 2026
Sep 30, 2026 (Q3 2026)	Sat, Nov 14, 2026	Mon, Nov 16, 2026
Dec 31, 2026 (Q4 2026)	Sun, Feb 14, 2027	Tue, Feb 16, 2027 (Mon Feb 15 is Presidents' Day)
Mar 31, 2027 (Q1 2027)	Sat, May 15, 2027	Mon, May 17, 2027
Jun 30, 2027 (Q2 2027)	Sat, Aug 14, 2027	Mon, Aug 16, 2027
Sep 30, 2027 (Q3 2027)	Sun, Nov 14, 2027	Mon, Nov 15, 2027
Dec 31, 2027 (Q4 2027)	Mon, Feb 14, 2028	Mon, Feb 14, 2028

We counted each date ourselves. Presidents' Day is the third Monday of February by federal law⁵. You can check the math against a real filing. Berkshire filed its Q4 2025 report on February 17, 2026, the first business day after the long weekend⁶.

So for the Q3 2026 filings: many sites say "November 14." That is day 45. But it is a Saturday, so the legal deadline is Monday, November 16, 2026. Expect a flood of filings in the days around then.

What a 13F shows, and what it hides

Here is what you get from a 13F filing:

• Long positions (stocks the manager owns, betting they go up) in US-listed stocks.
• Some ETFs, listed options (contracts to buy or sell a stock later) and convertible bonds.
• The share count and dollar value of each one, on the last day of the quarter.

Here is what you do not get:

• Short positions. A short is a bet that a stock will fall. The SEC tells managers not to report them¹. So a fund can look bullish on a stock it is actually betting against.
• Cash and bonds. Ordinary bonds and Treasury bills are not on the list⁴. A fund sitting mostly in cash can look fully invested.
• Most foreign stocks. Shares listed only abroad do not count. Berkshire owns big stakes in five Japanese trading houses, including ITOCHU and Mitsubishi⁷. None of them appear on its 13F.
• When they traded. You see one snapshot per quarter. A stock bought on day 1 and one bought on day 89 look the same.
• What happened since. The filing can arrive 45 days after the snapshot. By then the fund may have sold.
• Tiny positions. A manager may skip a holding under 10,000 shares and under $200,000 in value. Both tests must be met².
• Why they bought. There is no reasoning, no price paid, and no target.

That last point matters most. A 13F tells you what. It never tells you why, or at what price.

Confidential treatment: the holdings that show up late

Sometimes a manager is still buying a stock when the deadline arrives. If the world finds out, other traders can push the price up before the manager is done. So the law lets a manager ask the SEC to keep a holding secret for a while. This is called confidential treatment.

The manager must explain why secrecy is needed and how it would be harmed². The request can cover at most one year from the filing deadline². When the secrecy ends, the manager must file an amended 13F (a "13F-HR/A") that reveals the holding².

Berkshire is the classic example. Its 13F for September 30, 2023 did not show its Chubb stake. On May 15, 2024, Berkshire filed an amendment. It revealed 8,143,530 Chubb shares worth $1.70 billion as of that earlier date⁸. It happened again in 2025. An amendment filed August 14, 2025 revealed stakes in D.R. Horton, Lennar and Nucor, worth $1.11 billion in total as of March 31, 2025⁹.

The lesson: a 13F can be incomplete on purpose. Check for amendments.

How to read a 13F filing on SEC EDGAR, step by step

EDGAR is the SEC's free filing database. Here is how to find any manager's 13F filing.

1. Open the company search. Go to EDGAR company search and type the manager's legal name, such as "Berkshire Hathaway Inc."
2. Pick the right filer. Many funds have similar names. Check the city and the CIK, the SEC's ID number for each filer. Berkshire's is 0001067983⁶.
3. Filter to 13F. In the filing list, filter the form type to "13F." You want "13F-HR" (the holdings report). "13F-HR/A" is an amendment. "13F-NT" means another firm reports the holdings instead².
4. Open the latest 13F-HR. Check the "Period of Report" date. That is the snapshot date, not the filing date.
5. Read the cover page first. Look at "Table Entry Total" and "Table Value Total." Also look for a box saying confidential information was left out².
6. Open the information table. It is the second document in the filing. Pick the HTML view, not the raw XML.
7. Add up duplicate rows. One stock can appear on many rows, one per subsidiary or sub-account. Add the shares by CUSIP to get the real position.
8. Compare with last quarter. Open the prior 13F-HR and line up the share counts. A higher count means they bought. A lower one means they sold.

Worked example: Berkshire Hathaway's Q2 2026 13F filing

Let's read a real one. Berkshire filed its 13F for the quarter ended June 30, 2026 on August 14, 2026. That was day 45, right on the deadline¹⁰.

The cover page. It lists 89 table rows worth $299,253,556,246 in total¹⁰. It also lists 14 "other included managers." These are Berkshire units that own stock, such as GEICO, General Re and National Fire & Marine Insurance¹⁰. The confidential box is not checked¹⁰.

89 rows, but only 29 holdings. Apple alone takes 12 rows, one for each Berkshire unit that holds it. Add those rows and you get 227,917,808 Apple shares worth $65,950,296,923¹⁰. Divide the value by the shares and you get $289.36. That is Apple's closing price on June 30, 2026, the snapshot day. Across all rows, the 89 entries collapse into 29 distinct securities¹¹.

How concentrated it is. Here are the five biggest positions¹¹:

Holding	Shares	Value (June 30, 2026)	Share of 13F total
Apple	227,917,808	$65.95 billion	22.0%
American Express	151,610,700	$51.28 billion	17.1%
Coca-Cola	400,000,000	$32.51 billion	10.9%
Alphabet (Class A)	78,791,167	$28.16 billion	9.4%
Bank of America	483,394,015	$27.54 billion	9.2%

Three stocks make up half the reported portfolio. The top ten make up 88.5%¹¹. That is typical of Berkshire and very unlike an index fund.

Watch for two share classes. Alphabet has two listed classes, Class A (GOOGL) and Class C (GOOG). Each has its own row group. Add them together and Berkshire held $37.76 billion of Alphabet¹¹. That is more than its Coca-Cola stake.

What changed since March 31. Compare with the Q1 2026 filing and the moves pop out¹²¹¹:

• Bought more: Alphabet Class A rose from 54,249,798 to 78,791,167 shares (+45%). Delta Air Lines rose 44%.
• Sold some: Bank of America fell 5.9%. Kroger fell 22%. Capital One fell 58%.
• Sold all: Constellation Brands is gone.
• New: D.R. Horton, but only 3,564 shares worth $580,504.

Notice that D.R. Horton line. It is under 10,000 shares. But it is worth more than $200,000, so it still had to be reported². In a $299 billion portfolio, that is a rounding error. It is not a big new bet. So never treat every "new position" as a signal.

One more trap. The total value rose 13.7%, from $263.1 billion to $299.3 billion¹¹. That does not mean Berkshire bought $36 billion of stock. Apple's share count did not change, yet its value moved with the price. Compare share counts, not dollar values.

You can see the whole table, with every change already worked out, on our Berkshire Hathaway fund page. For the story behind each position, read our Warren Buffett portfolio guide.

How to see what stocks hedge funds own without EDGAR

EDGAR is free but slow. Free trackers do the adding and comparing for you. Ours is one of them:

• /funds lets you browse every tracked investor's latest 13F, free.
• /funds/moves shows the quarter's biggest buys and sells across all of them.
• Each fund page, like Berkshire's, adds up duplicate rows and flags new, added, cut and sold positions.

Want to follow a more active investor? See our Bill Ackman portfolio guide for how Pershing Square's 13F reads.

Does copying 13F filings work?

Copying the top picks from 13F filings is often called "cloning." The research is more mixed than the YouTube thumbnails suggest.

The case for it. A 2008 study looked at Berkshire's portfolio from 1976 to 2006. A copycat portfolio that bought Berkshire's stocks the month after they were disclosed beat the S&P 500 by 10.75% a year¹³. A 2008 paper on fund managers found their "best ideas" beat the market by 39 to 127 basis points a month (0.39% to 1.27%)¹⁴. A 2019 study used 13F data with the 45-day delay built in. A mix of hedge fund "conviction" and "consensus" picks beat the S&P 500 by 3.80% on average, from 2004 to 2019¹⁵.

The catches. Every one of these results comes with a fine print.

• Hindsight. We know Buffett is great because he did great. The Berkshire study itself warns about this selection bias¹³. Picking tomorrow's star is the hard part.
• The right managers only. The 2019 study found you must pick managers with long-term views. Copying everyone did not work as well¹⁵.
• Best ideas, not whole portfolios. The 2008 fund study found the edge sat in each manager's single highest-conviction stock, not the rest¹⁴.
• The delay. You buy up to 45 days late, after the price may have moved. You also never see the exit until the next filing.
• Missing pieces. You copy the long side without the shorts, cash or hedges that made the fund safe.

Our honest take. 13F filings are a great list of stocks worth studying. They are a poor list of stocks worth buying without your own homework. Use them to find ideas, then check the business yourself. Our guide on how to read a 10-K shows you how.

Questions

What is a 13F filing used for?

It shows the public which US stocks big investors own. Investors use it to find ideas and see what famous managers buy and sell. Companies use it to see who owns their shares.

When is the next 13F filing deadline?

For the quarter that ended September 30, 2026, day 45 is Saturday, November 14. So the deadline moves to Monday, November 16, 2026. The one after that is Tuesday, February 16, 2027.

Do 13F filings show short positions?

No. The SEC tells managers not to include them¹. A 13F only shows long positions, so it can make a fund look more bullish than it really is.

Are 13F filings free to see?

Yes. Every 13F filing is free on SEC EDGAR. Free trackers like our fund pages also show them already added up and compared.

Why is a fund missing a stock I know it owns?

The stock may be listed only abroad, or be under the small-position limit. It may be under confidential treatment. Or the fund sold it after the quarter ended.