InsiderFlow › Guides › How to Read a 13F Filing, Step by Step

How to read a 13F filing

Every quarter, big US funds disclose their holdings to the SEC. Knowing how to read them means seeing smart money's cards — if you avoid the interpretation traps.

Where to find them

On the SEC's EDGAR database, searching the fund's name. They're free but unfriendly: tables of tickers, CUSIPs and nominal values. Tools like InsiderFlow make them readable and explain them.

What actually matters

New positions and complete exits say more than marginal adjustments. Weight matters too: a stock at 10% of the portfolio is a conviction, one at 0.1% is noise. And compare multiple quarters: progressive accumulation is the strongest signal.

The 5 mistakes of 13F copycats

1) Forgetting the delay: data is up to 45 days old — the fund may have already sold. 2) Ignoring shorts: the 13F shows only long positions — a stock can be one leg of a complex strategy. 3) Copying quant funds like Citadel, whose thousands of positions reflect no "convictions". 4) Ignoring fund size relative to the stock. 5) Buying without your own thesis: a 13F is a research starting point, not an automatic signal.

Who to start with

Concentrated, low-turnover portfolios are the most informative: Berkshire Hathaway, Pershing Square, Greenlight. Their positions last years, making the 45-day delay almost irrelevant.