What Is a 13F Filing? A Plain-English Guide
Every quarter, the biggest investors in the world have to show their hand. The disclosure is called a Form 13F, and once you know how to read it you can study exactly which U.S. stocks legendary investors own. Here's what a 13F includes, and just as importantly, what it leaves out.
Who has to file a 13F?
The SEC requires any institutional investment manager with discretion over more than $100 million in U.S.-listed securities to file a Form 13F-HR each quarter. That sweeps in hedge funds, asset managers, insurers, pensions, and family offices — including household names like Berkshire Hathaway, Pershing Square, and Baupost Group.
What a 13F shows
Each filing lists the manager's long positions in U.S.-listed stocks and options as of the last day of the quarter: the security name, its CUSIP identifier, the number of shares, and the market value. By comparing two consecutive filings you can infer what the investor bought, added to, trimmed, or sold entirely.
That's exactly what Superinvestor Tracker does automatically: it ingests the raw filings from SEC EDGAR, backfills tickers, and reconstructs each investor's quarter-over-quarter moves.
What a 13F does NOT show
A 13F is an incomplete picture. It excludes short positions, cash, bonds, commodities, foreign-listed shares, and most derivatives. It is filed up to 45 days after quarter end, so the data is already weeks old. And it never reveals an investor's reasoning or conviction. Treat 13F data as a research starting point — not a signal to copy blindly.
How to actually use 13F data
The most useful angles are consensus (stocks that many great investors hold at once), change (what they bought and sold last quarter), and concentration (how heavily they bet on their top ideas). Superinvestor Tracker computes all three across dozens of investors so you don't have to parse XML by hand.