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Nov 4, 2025 · 9 min read

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.

Ever wonder what Warren Buffett is buying? Or what positions Bridgewater or Citadel are holding? The SEC requires large investment managers to disclose their holdings every quarter through Form 13F.

This guide explains how 13F filings work, where to find them, and how to use this data in your investment research—without falling into common traps.

What is a 13F Filing?

Form 13F is a quarterly report that institutional investment managers must file with the SEC. It discloses their equity holdings as of the end of each quarter.

Key facts:

  • Who files: Investment managers with $100M+ in qualifying assets
  • What's reported: All "Section 13(f) securities" (mainly U.S. stocks and some options)
  • When filed: Within 45 days after quarter end
  • Frequency: Quarterly (March 31, June 30, September 30, December 31)

The result: a public database of what the largest investors in the world are holding.

Who Files 13F Reports?

Any investment manager controlling $100 million or more in 13(f) securities must file. This includes:

Hedge Funds

  • Bridgewater Associates
  • Citadel
  • Renaissance Technologies
  • Two Sigma
  • D.E. Shaw

Asset Managers

  • BlackRock
  • Vanguard
  • Fidelity
  • State Street
  • T. Rowe Price

Insurance Companies

  • Berkshire Hathaway
  • MetLife
  • Prudential

Pension Funds

  • CalPERS
  • New York State Teachers
  • Texas Teachers

Endowments

  • Yale
  • Harvard
  • Stanford

Family Offices

  • Some family offices file (Bill Gates Foundation)
  • Others may be exempt under certain structures

What 13F Filings Show

Included in 13F

  • U.S. exchange-traded stocks
  • American Depositary Receipts (ADRs)
  • Exchange-traded funds (ETFs)
  • Equity options (calls and puts)
  • Convertible bonds (sometimes)

NOT Included in 13F

  • Short positions (this is a major limitation)
  • Non-U.S. stocks traded on foreign exchanges
  • Fixed income (bonds, except convertibles)
  • Private investments
  • Derivatives other than equity options
  • Cash positions

Important: A 13F only shows the long equity book. You're seeing half the picture at most. A hedge fund could be net short while the 13F makes them look bullish.

How to Read a 13F Filing

13F filings have a standard structure:

Cover Page

  • Manager name and address
  • Report period (quarter end date)
  • Total holdings count and value

Information Table

The meat of the filing. For each holding:

Column What It Shows
Name of Issuer Company name
Title of Class Type of security (COM = common stock)
CUSIP Security identifier
Value (x$1000) Market value in thousands
Shares/PRN Amount Number of shares held
SH/PRN Shares (SH) or principal (PRN)
Put/Call For options only
Investment Discretion SOLE, SHARED, or NONE
Voting Authority Sole, shared, or none

Reading the Numbers

Example entry:

APPLE INC          COM      037833100    5,234,000    25,400    SH    SOLE

This means: The fund holds 25,400 shares of Apple common stock worth $5.234 billion.

The 45-Day Delay Problem

Here's the catch: 13F data is old by the time you see it.

Timeline:

  • Quarter ends: March 31
  • Filing deadline: May 15 (45 days later)
  • You read it: May 16 or later

By mid-May, you're seeing positions from March 31—nearly seven weeks old. In volatile markets, a lot can change.

What This Means for Investors

  • Don't assume the fund still holds the position
  • The price you'd pay is different from their cost basis
  • Use 13F for research, not real-time signals

Some Funds Delay Intentionally

Hedge funds often file on the last possible day to minimize information leakage. A few even request confidential treatment for positions they're still building.

Famous 13F Filers to Watch

Berkshire Hathaway

Why it matters: Warren Buffett's long-term value bets. Berkshire's moves make headlines.

Recent notable positions: Apple (massive), Bank of America, American Express, Coca-Cola

How to interpret: Buffett thinks in decades. These are buy-and-hold positions, not trades.

Bridgewater Associates

Why it matters: World's largest hedge fund, known for macro and risk parity strategies.

Note: Their positions reflect systematic strategies, not stock-picking opinions.

Renaissance Technologies

Why it matters: The most successful quant fund ever (Medallion Fund). Though the 13F mainly shows their institutional funds, not Medallion.

How to interpret: These are algorithmically selected positions. The logic isn't apparent from holdings alone.

Bill Ackman (Pershing Square)

Why it matters: Activist investor who makes concentrated bets and pushes for change.

How to interpret: Few positions, high conviction. His thesis often becomes public through presentations.

Michael Burry (Scion Asset Management)

Why it matters: Famous for "The Big Short." His contrarian positions get attention.

Note: He trades actively. 13F positions may be gone by publication.

How to Use 13F Data

Idea Generation

Scan 13Fs from respected investors for companies you haven't considered. If multiple smart investors own something, it's worth researching.

Process:

  1. Find a manager whose style matches yours
  2. Review their top holdings
  3. Research companies you don't already know
  4. Make your own decision—don't copy blindly

Thesis Validation

Already researching a company? Check if institutional investors own it.

Questions to ask:

  • Do any value investors own this stock?
  • Is institutional ownership increasing or decreasing?
  • Who sold recently, and why might they have sold?

Crowded Trade Detection

If too many funds own the same stock, it may be "crowded." Crowded trades can unwind violently when everyone heads for the exit.

Warning signs:

  • Many hedge funds own the same small number of stocks
  • Position sizes are large relative to trading volume
  • The stock is widely discussed as a "favorite"

Management Quality Signal

For smaller companies, institutional ownership can signal quality. Smart money tends to avoid frauds and poorly managed companies.

But be careful: Institutions have been fooled too. Don't skip your own research.

13F Analysis Strategies

New Position Analysis

When a respected investor starts a new position:

  1. Note the size (large = high conviction)
  2. Research why they might have bought
  3. Check if other smart investors bought too
  4. Consider the timing—what was the price then vs. now?

Position Increase Analysis

Increasing an existing position suggests continued conviction:

  1. How much did they add?
  2. What was the stock doing? (buying into weakness = bullish)
  3. Are they averaging down or pyramiding up?

Exit Analysis

When a fund exits entirely:

  1. Did something change at the company?
  2. Was it forced selling (redemptions, strategy change)?
  3. Are other holders selling too?

Concentration Analysis

Looking at a fund's portfolio overall:

  1. How many positions? (10 = concentrated, 500 = diversified)
  2. What's the top 10 as % of portfolio?
  3. Any sector concentrations?

Common 13F Mistakes

Mistake 1: Copying Positions Blindly

The fund bought at different prices, has different time horizons, and knows things you don't about their overall portfolio. A position that makes sense for them might not make sense for you.

Mistake 2: Ignoring the Delay

By the time you see it, they might have sold. Or doubled down. You don't know.

Mistake 3: Missing the Short Book

13F shows longs only. A fund might be net short a sector while appearing bullish from the 13F alone.

Mistake 4: Confusing Correlation with Causation

Just because smart money owns something doesn't mean it will go up. They're often wrong, especially in aggregate.

Mistake 5: Chasing Yesterday's Winners

The positions that did well are visible. The ones that lost money are less discussed. Survivorship bias distorts perception.

Where to Find 13F Filings

SEC EDGAR

The official source: SEC EDGAR

Search by manager name, then look for "13F-HR" filings.

Earnings Feed

Browse 13F and other institutional filings on Earnings Feed. Filter by form type to find what you need.

WhaleWisdom

A dedicated 13F database with screening tools and historical data analysis.

Dataroma

Free aggregation of superinvestor portfolios. Good for quick scanning.

13F Filing Schedule

Quarter End Filing Deadline
March 31 May 15
June 30 August 14
September 30 November 14
December 31 February 14

Mark your calendar. The days after these deadlines see heavy 13F-related news coverage.

Related Filings

13F isn't the only way to track institutional activity:

13D/13G (Beneficial Ownership)

Filed when someone acquires 5%+ of a company's stock.

  • 13D: Activist investors with intent to influence
  • 13G: Passive investors with no activist intent

These are filed within 10 days of crossing 5%, much faster than 13F.

Form 4 (Insider Trading)

Filed by company insiders (executives, directors) within 2 days of trading. Track Form 4s on Earnings Feed.

13F vs. 13D/G Comparison

Filing Who Files Timing What's Shown
13F $100M+ managers 45 days after quarter All equity holdings
13D 5%+ activist owners 10 days after crossing 5% Single company position
13G 5%+ passive owners 45 days after year end Single company position

Building a 13F Research Process

Quarterly Review (Post Filing Deadlines)

  1. Check 13Fs from 5-10 managers you respect
  2. Note new positions and significant changes
  3. Add interesting companies to your research list
  4. Look for crowding (same stocks appearing everywhere)

Per-Stock Research

When researching a specific company:

  1. Check institutional ownership percentage
  2. Identify notable holders
  3. See if ownership is increasing or decreasing
  4. Research any recent 13D/G filings

Contrarian Signals

Sometimes the absence of institutional ownership is interesting:

  • Why don't smart investors own this?
  • Is it too small? Too risky? Or overlooked?

Summary

13F filings give you a window into how professional investors are positioned. But it's a foggy window—delayed, incomplete (no shorts), and reflects past decisions.

Use 13F data to:

  • Generate investment ideas
  • Validate your research
  • Identify crowded trades
  • Track institutional trends

Don't use 13F data to:

  • Copy positions blindly
  • Make time-sensitive decisions
  • Assume you have complete information
  • Skip your own research

The best investors use 13F as one input among many, not as a trading system.

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