Understanding SEC institutional holdings: Form 13F
Learn what institutional holdings reports tell you, how to read a Form 13F position, and what to check before comparing managers or quarters.
By Chad Mazzola
Which stocks does a large investment firm hold? How big are its positions, and how have they changed?
SEC Form 13F helps answer those questions. It gives you a view of the securities a manager reports holding at the end of a quarter. But it doesn't show every investment, tell you when trades happened, or identify what the manager holds today.
Here's how to read these reports and understand what the numbers mean.
Who files Form 13F?
Institutional investment managers generally must file when they exercise investment discretion over at least $100 million in securities covered by the SEC's 13F reporting rules. Investment discretion means having authority to decide which securities to buy or sell.
The managers can include investment advisers, banks, insurance companies, and pension funds. Their reports can cover investments across several funds or client accounts, so a manager's filing isn't necessarily the portfolio of one fund or one person.
Two names matter: the manager files the report, and the issuer is the company or fund whose security appears in a holding. Berkshire Hathaway reporting Apple shares makes Berkshire the manager and Apple the issuer.
Quarter-end holdings and filing dates
Form 13F reports holdings at the end of a calendar quarter. Managers generally have up to 45 days after quarter end to file, so the information is already several weeks old when you receive it.
For example, Berkshire Hathaway's report for 31 March 2026 was filed on 15 May. Its positions describe the end of March, not the day in May when the report became public.
That distinction matters in your application. A label such as “Holdings at 31 March” tells users what the data represents. “Current holdings” suggests something the filing can't establish.
How to read a reported holding
The report's information table contains the holdings. Each row identifies a security and gives its reported quantity and market value, along with details about the managers involved.
Start with these fields:
| Field | What it tells you |
|---|---|
| Issuer, security class, and CUSIP | Which security the row describes. A CUSIP identifies a security; the company name alone doesn't distinguish different share classes |
| Quantity and quantity type | How much is reported. SH means shares; PRN means principal amount, such as the face amount of debt |
| Value | The position's market value at quarter end, rather than what the manager paid for it |
| Put or call | Whether the row describes an option position rather than a holding of the shares themselves |
| Investment discretion and voting authority | Who has authority over investment decisions and voting. These are separate questions |
Options give their holder a right to buy a security (a call) or sell it (a put). For an option, the reported quantity refers to the underlying shares, not the number of contracts. Its reported value also refers to the underlying securities, not the price of the options themselves. A put position with a large reported value doesn't mean the manager spent that amount buying puts.
The SEC's Form 13F FAQ explains these fields and the reporting rules behind them.
A real example: Berkshire's Apple holding spans 12 rows
In Berkshire's March 2026 information table, the first Apple row reports:
- Security: Apple common stock, CUSIP 037833100
- Quantity: 692,000 shares
- Reported market value: $175,622,680
That isn't Berkshire's entire reported Apple position. Apple common stock appears on 12 rows, with different references in the “other manager” column. Those references point to the managers listed on the report's summary page.
Adding the share quantities across those 12 rows gives 227,917,808 shares. Taking only the first matching row would dramatically understate the holding. Treating each row as a different investment would also misrepresent it.
For a portfolio view, group the matching security and position type. Keep share classes, puts, and calls separate, and preserve the individual rows when you need their manager and voting details.
What changes between quarters can tell you
Comparing reports lets you see how a reported position changed. It doesn't give you a list of trades.
A higher market value doesn't necessarily mean more buying. The price may have risen while the share count stayed the same.
A higher share count doesn't tell you the purchase date or price. Corporate actions such as stock splits can also change quantities. A manager could trade in and out of a position during the quarter without those trades appearing in the final holdings.
Describe the change you can actually see: “Reported shares increased between March and June” is more precise than “The manager bought these shares in June.”
Check notices and amendments before comparing
13F-HR contains a holdings report. 13F-NT is a notice that other managers report the holdings. It has no holdings table of its own, which doesn't mean the manager has no investments.
An amended holdings report, 13F-HR/A, can either restate the earlier table or add holdings omitted from it. Those do different jobs: a restatement replaces the table, while an addition supplements it. Using only the latest filing can miss positions; adding every filing together can double-count them.
What Form 13F leaves out
The report covers securities on the SEC's official 13F list, primarily US exchange-traded stocks and certain other securities. It isn't a complete account of everything the manager owns.
Cash and many other assets aren't included. The reported total therefore isn't the manager's total assets under management. A position representing 10% of its reported 13F holdings doesn't necessarily represent 10% of its whole portfolio.
Short positions aren't reported. You can't use the table alone to work out a manager's net exposure to a company, or assume a large shareholding represents its entire view of that investment.
Some holdings may be absent from the public report. Confidential treatment can delay disclosure, and the rules allow certain small positions to be omitted. A missing row alone isn't proof of a sale.
Using institutional holdings in your application
Keep the manager, reporting quarter, security, and position type clear. Apply amendments correctly, then compare like-for-like positions. That gives users a useful picture of reported holdings without turning a quarterly disclosure into a claim about today's portfolio or yesterday's trades.
Chadwin provides institutional manager records, reported holdings, and grouped positions through its API. See the institutional holdings guide for the available data and endpoints.