Lists of “what Buffett is buying” all come from one public document: Form 13F. Any institutional investment manager with over $100 million in US-listed stocks must file one with the SEC within 45 days of each quarter’s end. Berkshire Hathaway files one too, and that’s where every “Buffett portfolio” article gets its numbers.
What a 13F shows
- Every long position in US-listed stocks (and some options and convertibles) at the end of the quarter: the company, the number of shares and their value.
- Compared with the previous quarter’s filing, which positions are new, which were added to or trimmed, and which were sold entirely.
What it hides
- It’s late. A snapshot of the last day of the quarter, published up to 45 days later. The fund may have sold since.
- It’s one-sided. Short positions, cash, bonds and most foreign stocks aren’t listed, so a position can look like a bet when it’s a hedge.
- No reasons and no prices. You see what they own, not why, what they paid, or how big it is relative to their conviction.
- Some positions are delayed. Managers can ask the SEC to keep a position confidential while they’re still buying.
How to use 13Fs without copying blindly
Treat fund filings as a second opinion, not a shopping list. The useful question isn’t “what did a famous fund buy?” but “is a company that already looks good and cheap also attracting careful money, or being sold by it?”
That’s how they’re used here. Every 13F is parsed from SEC EDGAR within the hour it’s filed, compared with the prior quarter and matched to tickers. Each of the 499 company pages tracks how many funds hold it and which notable managers are buying or selling, next to the company’s own fundamentals. See the latest filings as they land, or read how the rule judges the companies themselves.