Every quarter, ~6,000 institutional investors must publicly disclose their U.S. stock holdings through a form called 13F-HR. It's filed with the SEC, it's free to access, and it lets you see exactly what Berkshire, Vanguard, and thousands of hedge funds own.
Here's the complete beginner's guide.
The basics
Who files: Any institutional investment manager with $100M+ in qualifying U.S. equity securities.
What they disclose: Every long position in U.S.-listed stocks and ETFs — name, shares held, and market value.
When: Within 45 days of each quarter end (Feb 14, May 15, Aug 14, Nov 14).
Where: SEC EDGAR — publicly available, free.
Who files 13F?
The filer universe includes:
| Category | Examples | What their 13F shows |
|---|---|---|
| Hedge funds | Berkshire, Bridgewater, ARK | Active stock-picking decisions |
| Asset managers | Vanguard, Fidelity, BlackRock | Mostly index-driven holdings |
| Banks | Goldman Sachs, JPMorgan | Trading desk + wealth management |
| Insurance cos | Northwestern Mutual, MetLife | Investment portfolio backing policies |
| Market makers | Jane Street, Susquehanna | Hedging inventory, not investments |
| Pension funds | CalPERS, state systems | Long-term institutional allocations |
~6,000 institutions file each quarter — from $7T Vanguard to $100M family offices.
What 13F shows vs. what it doesn't
✅ Included
- All long positions in U.S.-listed equities and ETFs
- Share count and market value per position
- Investment discretion and voting authority
❌ NOT included
- Short positions (invisible)
- Non-U.S. securities
- Bonds, cash, commodities, real estate
- Private investments
- Most derivatives (swaps, futures)
- Transaction dates or prices
Critical limitation: A hedge fund that's 50% long / 50% short looks 100% long in a 13F. You're seeing half the portfolio.
The 45-day lag
This is the most important thing to understand:
- Quarter ends (Dec 31)
- Filing deadline (Feb 14 — 45 days later)
- You read it (Feb 20+)
By the time you see Q4 data, it's 7-8 weeks old. The manager may have already changed positions. 13F data is a rearview mirror, not a windshield.
What 13F data IS useful for
1. Tracking conviction over time
A fund holding AAPL for 8 consecutive quarters with growing size = persistent conviction.
2. Finding consensus shifts
3+ respected managers entering the same name in one quarter = emerging institutional consensus.
3. Identifying entries and exits
New positions (especially >1% of portfolio) = fresh conviction. Complete exits = lost conviction.
4. Understanding manager DNA
Concentration, position count, ETF ratio, and sector weights classify what kind of manager you're looking at.
5. Building context for your own research
13F data tells you who else owns what you own — and whether they're adding or trimming.
What 13F data is NOT useful for
- Day trading: Data is 45+ days old
- Copy trading: By the time you see it, the opportunity may be gone
- Understanding hedge strategies: You only see the long book
- Short-term predictions: Institutional positions are held for quarters/years
How to get started
Step 1: Pick 5 managers to follow
- 1 value investor (Berkshire)
- 1 growth manager (ARK or Jennison)
- 1 passive baseline (Vanguard)
- 1 quant (D.E. Shaw)
- 1 activist (Elliott)
Step 2: Read their latest filing
Note: top 10 holdings, concentration (top-10 weight), position count, any ETFs.
Step 3: Compare to previous quarter
What's new? What's gone? What grew or shrank significantly?
Step 4: Cross-reference
Did multiple managers on your list make the same move? Convergence = signal.
Step 5: Repeat quarterly
The value compounds over time. After 4 quarters, you'll understand each manager's behavior well enough to spot anomalies.
The 13F ecosystem
13F is just one piece of the SEC disclosure puzzle:
| Filing | What it shows | Timing |
|---|---|---|
| 13F-HR | Institutional equity holdings | Quarterly (45-day lag) |
| Form 4 | Insider transactions (buy/sell) | Within 2 business days |
| Schedule 13D | >5% activist ownership | Within 10 days |
| Schedule 13G | >5% passive ownership | Annually / semi-annually |
| DEF 14A | Full beneficial ownership | Annually (proxy season) |
Used together, these filings give you a comprehensive view of who owns what, who's buying/selling, and who might be planning changes.
Originally published at 13F Insight
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