Two filings, two questions
A Form 4 answers the question “what did this insider just trade?” A 13F answers “what did this fund own at the end of last quarter?” They come from different rules, cover different people and arrive on very different schedules.
Side by side
| Form 4 | Form 13F | |
|---|---|---|
| Who files | Officers, directors and anyone owning more than 10% of a company’s shares | Investment managers with at least $100 million in 13(f) securities |
| What it covers | One company’s shares, for one person or entity | Every covered U.S.-listed holding the manager has |
| What it shows | Each trade: date, buy or sell, shares, price, holdings after | A snapshot of holdings on the last day of the quarter |
| How fast | Within two business days of the trade | Within 45 days after the quarter ends |
| Shows sales? | Yes, every one | Only as a smaller or missing position next quarter |
| Shows prices? | Yes | No, only quarter-end values |
When one investor files both
A fund that owns more than 10% of a company becomes an insider of that company under Section 16. From then on, it must file a Form 4 every time it trades that stock, in addition to its regular 13F. Those Form 4s are the fastest way to follow a big fund’s moves, but only in companies where it has crossed 10%.
Which one to use
For fresh information about a specific company, read the Form 4s on its insider trading page. For a picture of what a manager believes across its whole portfolio, read the 13F on its fund page. They work best together: the 13F tells you where a fund stands, and any Form 4s tell you what it did since.
Examples
Berkshire Hathaway and Bank of America, 2024. Berkshire owned more than 10% of Bank of America, so when it began selling in mid-July 2024 it had to report each sale on a Form 4 within two business days. The public could follow the selling almost in real time through the summer. On October 10, 2024, a filing showed Berkshire’s stake had fallen to about 775 million shares, roughly 9.99% of the bank. Below 10%, the two-day reports stopped. From then on, the only regular update was Berkshire’s 13F, showing its position at the end of each quarter.
Berkshire Hathaway and Apple, 2024. Berkshire never owned close to 10% of Apple, so its Apple trades produced no Form 4s. When it cut its Apple stake roughly in half during the second quarter of 2024, the public learned about it only when Berkshire reported quarterly results in early August, and then in the 13F filed on August 14, 2024. One investor, two very different levels of visibility.
Explain it like I’m 13
Imagine two kinds of reports at school. One is a note the class captains must hand in within two days whenever they swap a seat. You find out fast, but only about the captains.
The other is a seating chart for the whole class, drawn on the last day of term and handed in six weeks later. You see everyone, but it is old news.
Form 4 is the quick note from the captains, who are a company’s insiders. A 13F is the seating chart for a fund’s whole portfolio.
Questions about this guide? Pal reads it with you and answers in plain English.
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