13F Filings: How to See What Hedge Funds Are Buying
Learn how to find and analyze 13F filings to see what institutional investors like Berkshire Hathaway, Bridgewater, and Citadel are holding.
If you’ve ever wondered, “What is Buffett buying right now?” or “What’s actually inside Bridgewater’s book?” you’re looking for one thing: Form 13F.
The SEC forces large investment managers to reveal a slice of their portfolio every quarter. Those reports are public, free, and surprisingly easy to access once you know where to look. They’re also very easy to misuse.
This guide walks through what a 13F is, what it does and doesn’t show, how to read one, and how to turn it into something useful for your own research—without turning your portfolio into a delayed, low‑information copy of someone else’s.
What Is a 13F Filing, Really?
Form 13F is a quarterly position report. Any institutional investment manager that controls at least $100 million in “13(f) securities” has to send the SEC a list of those holdings four times a year.
The basic idea is transparency: regulators and the public get a view into how large, market‑moving investors are positioned. In practice, it means you can see the long U.S. equity book of:
- Hedge funds and quant shops
- Large mutual fund and ETF managers
- Pension funds and insurance companies
- Some endowments and family offices
Each report shows positions as of the quarter end, not the day it’s filed. That’s an important nuance: if a fund reports as of March 31, they have until mid‑May to file. By the time you see it, the information is already up to 45 days old.
Even with that lag, 13Fs are still a goldmine for understanding what sophisticated investors have been willing to own.
Who Has to File 13F Reports?
The trigger isn’t “hedge fund” or “Wall Street shop,” it’s simple: $100 million or more in qualifying securities under management.
That includes the obvious names—multi‑strategy hedge funds, long‑only mutual fund complexes, giant ETF providers—but also some investors people don’t always think about:
- Big pension plans and sovereign funds
- Insurance companies that run sizable equity portfolios
- University endowments with internal public equity teams
- Certain family offices and foundations, depending on structure
Berkshire Hathaway files because it runs a large equity portfolio inside an insurance conglomerate. Bridgewater files. So do fund complexes like BlackRock or Fidelity. Smaller, nimble funds under the threshold never show up; some family offices are structured in ways that keep them out of the 13F regime entirely.
The point: 13F is a window into the bigger end of the pool, not a complete map of all “smart money.”
What 13F Shows—and What It Hides
One of the easiest ways to get into trouble with 13Fs is to forget what’s missing.
What you do see:
- Long positions in U.S. exchange‑traded equities
- Many U.S.‑listed ETFs and some ADRs
- Certain equity options (calls and puts) when they’re part of the long book
What you don’t see:
- Short positions of any kind
- Most derivatives beyond listed equity options
- Bonds and most fixed income instruments
- Non‑U.S. stocks that only trade abroad
- Private investments, convertibles in many cases, cash, and cash equivalents
The result: you’re looking at a cropped picture. A market‑neutral fund might show a big long position in a sector on its 13F while being just as large short in other names you never see. A global macro fund might have a small U.S. stock sleeve that looks random relative to where they actually make money.
If you treat a 13F as a complete portfolio, you’ll over‑interpret. It’s better to think of it as “the U.S. long equity slice of this manager’s world” and nothing more.
How a 13F Is Structured
Once you open a 13F, you’ll see the same basic layout over and over. The format is standardized, which is nice once you get used to it.
The cover page is housekeeping: manager name and address, the quarter end date, and a summary of how many positions and how much market value is being reported. You glance at it to confirm you’re looking at the right manager and period.
The information table is where the actual holdings live. Each row is a position. Typical columns include:
- The issuer name (for example, “APPLE INC”)
- The class (“COM” for common stock, or a specific class/series)
- The CUSIP (identifier you can use with other data sources)
- The value, usually in thousands of dollars
- The number of shares or principal amount
- A field indicating whether it’s a call or put (for options)
- Notes on investment discretion and voting authority
A simplified line might look like this (spacing aside):
APPLE INC – COM – 037833100 – 5,234,000 – 25,400 – SH – SOLE
Translated: the manager reports holding 25,400 shares of Apple common stock, with a market value of $5.234 billion as of the reporting date, held with sole investment discretion.
You don’t need to obsess over voting authority. As an outside investor, you care more about what they thought was worth owning in size, not whether they have shared voting arrangements on certain shares.
The 45‑Day Lag: Why Timing Matters
On paper, the rule is clear: managers have 45 days after the end of each quarter to file. In practice, most hedge funds wait until the last moment. They have no incentive to give competitors—and the entire internet—an earlier look at their playbook.
The timeline for a March quarter looks like this:
- March 31: portfolio snapshot date
- Early April: internal reporting and audits
- By May 15: 13F is prepared and filed
- Mid‑May onward: investors and data sites digest it
So when you pull up a 13F in mid‑May, you’re looking at positions as they stood on March 31. The manager may have added, trimmed, or exited positions entirely since then. In quiet markets that might not matter much; during volatile periods, the gap can be huge.
There’s no way around this. You use 13Fs for position context and idea sourcing, not for precision timing.
Why People Care About Specific 13F Filers
Not all 13Fs are equally interesting.
Some managers run massive, diversified portfolios where the top positions are just the usual mega‑caps everyone owns. Others run concentrated, high‑conviction books where every line is a deliberate bet.
Berkshire Hathaway is the classic example of the latter. Its 13F effectively shows you a set of long‑term equity holdings selected by Warren Buffett and his team. Positions tend to be large, slow‑moving, and tied to clear value‑driven theses—Apple, long‑held financials, branded consumer names. When Berkshire adds or exits, headlines follow.
An activist fund like Pershing Square is another case where the 13F is particularly interesting. They typically run a small number of big positions. When a new name appears in size, you can almost guarantee there’s a thesis deck either out already or on the way.
Systematic and quant shops are different. A firm like Renaissance or a large multi‑manager platform may hold dozens or hundreds of names driven purely by algos and risk models. Their 13F can still be interesting in aggregate but is much less useful at the individual stock level. You’re not going to reconstruct the strategy from the holdings.
The meta‑point: pick a handful of managers whose style and time horizon make sense to you, and pay more attention to their filings than to a hundred random funds.
Turning 13F Data Into Something Useful
Used well, 13Fs are a great way to broaden your radar and sanity‑check your own ideas. Used badly, they turn you into a lagged shadow of someone else’s strategy.
Three broad uses tend to be genuinely helpful.
1. Idea Sourcing
The simplest use is to scan a manager’s top positions and ask, “What do they see that I might be missing?”
If a long‑term, fundamentals‑focused fund has owned a company for years and quietly keeps adding, that’s an invitation to look closer. If several independent investors you respect all own the same mid‑cap, maybe it belongs on your research list.
The important bit is what comes next: you still do your own work. The fact that Fund X bought something doesn’t answer why they bought it, how they sized it, or how it fits with the rest of their book. Treat 13F holdings as a reading list, not as trade alerts.
2. Thesis Cross‑Check
When you’re already researching or owning a name, it’s natural to wonder who else is in there with you.
Looking across a few quarters of 13Fs and ownership data can answer questions like:
- Has institutional ownership been rising or falling?
- Did a well‑known value investor quietly exit at the same time you’re thinking of adding?
- Is the stock so widely held by hedge funds that it might behave like a crowded trade on bad news?
None of these are decisive on their own, but they give you context. If you think you’ve found a hidden gem yet half of the Tiger cubs already own 5% each, maybe it’s less “hidden” than you thought.
3. Portfolio Reading
Sometimes you learn more by looking at a manager’s 13F as a whole than by focusing on any single line item.
You can ask: how concentrated is this portfolio? Are there big sector tilts? Is the top ten half the book or a quarter of it? Does this quarter look like a clean evolution of the previous one, or like a strategy that’s been scrambled by redemptions and volatility?
This is particularly useful if you’re thinking about investing in a fund itself, but even as an equity investor it teaches you how different people express their views in position sizing, not just stock picking.
Common 13F Traps
Because the data is concrete—tickers and share counts and dollar values—it’s tempting to treat it as harder information than it really is.
A few failure modes show up again and again:
Copy‑and‑paste portfolios. Simply recreating someone else’s top ten based on a months‑old snapshot, without understanding the thesis or the risk profile, is a fast way to own a collection of positions that don’t fit your goals or temperament.
Forgetting about shorts. A sector tilt that looks bullish on a 13F might actually be paired with an even larger short book you never see. You’re seeing one leg of a complex structure and assuming it stands alone.
Ignoring time horizon. A long‑only manager with low turnover and a five‑year view plays a different game than a fast‑trading fund trying to capture quarterly dislocations. Borrowing positions from the latter when you can’t match their speed is asking for trouble.
Confusing fame with fit. Berkshire’s holdings reflect Buffett’s mandate, cost of capital, and constraints. They can be useful to study, but they’re not automatically appropriate for your situation—or your psychology.
The safest stance is to treat 13Fs as descriptive, not prescriptive: “here’s how this manager was positioned at this point in time,” not “here’s what you should do now.”
Where to Actually Get 13Fs
You don’t need a premium data service to read 13Fs. There are three tiers of access, depending on how much polish you want.
At the base layer, there’s SEC EDGAR. You can search by manager name and filter for “13F‑HR” filings. It’s clunky but authoritative; every other tool ultimately relies on the same source.
On top of that, there are more user‑friendly front ends and aggregators. With a tool like Earnings Feed, you can filter the live filings stream or a company’s profile page by form type and see 13Fs alongside 10‑Ks, 10‑Qs, 8‑Ks, and Form 4s. Other specialized sites focus almost entirely on 13F aggregation and portfolio views.
At the practical level, it doesn’t matter which interface you choose as long as:
- You can easily pull up the latest filing for a manager.
- You can jump to older quarters for comparison.
- You can export or at least scan the information table without going cross‑eyed.
Once you have that, you’re in business.
How 13F Fits With 13D/G and Form 4
13F is only one piece of the institutional disclosure puzzle.
When a single investor crosses 5% ownership in a specific company, you may also see:
- Form 13D, if they intend to be active—pushing for changes, board seats, transactions.
- Form 13G, if they’re claiming to be passive and not angling for control.
Those filings are position‑specific and often more timely than 13F. An activist 13D can be filed within ten days of crossing the threshold and can move a stock immediately, because it signals intent, not just ownership.
At the company‑insider level, Form 4 reports trades by executives and directors, typically within two business days. That’s a different lens entirely: you’re watching what management is doing with its own stock, not what outside institutions are doing.
Used together:
- 13F gives you a snapshot of institutional long equity positioning.
- 13D/13G give you early knowledge of big, engaged shareholders.
- Form 4 gives you real‑time signals from insiders inside the company.
You don’t need to track all of them obsessively, but knowing what each does helps you avoid mixing them up.
A Lightweight 13F Routine
You don’t have to become “the 13F person” to benefit from these filings. A simple rhythm is enough.
Once a quarter, a few days after the filing deadlines, you can:
- Pull up 13Fs for three to ten managers whose style you respect.
- Note any new, sizable positions and any abrupt exits.
- Add two or three unfamiliar companies that keep popping up to your research list.
When you’re already digging into a stock, you can:
- Check who owns meaningful stakes and whether that’s changed over the last few quarters.
- Scan for recent 13D/13G filings if ownership is concentrated.
- Decide whether the current shareholder base makes you more or less comfortable with the risk profile.
If you want the filings to come to you rather than chasing them:
- Create a free Earnings Feed account, add your watchlist names, and use the filings feed to see 13Fs and related forms as they appear.
That’s it. No need for elaborate 13F screens or reverse‑engineering someone’s entire strategy. You just fold these disclosures into your normal research diet.
Closing Thoughts
13F filings are one of the few places where the curtain lifts and you can see, in concrete detail, how large investors chose to express their views in public markets. They’re delayed, incomplete, and easy to misinterpret—but they’re still valuable.
If you treat them as:
- A source of ideas (“what are thoughtful investors looking at?”),
- A second opinion on names you already care about, and
- A way to learn how different strategies actually look in position form,
you’ll get most of the upside with far less of the pain.
Just remember the constraint: you’re looking at what someone owned weeks ago, through a partial lens, without knowing everything else on their book. Use that information to sharpen your own thinking, not to turn off your brain and copy someone else’s trades.