Short answer. A 13F filing is a list of the US-listed stocks a large investment manager held on the last day of a quarter. It shows what they owned then. It does not show what they own today, what they sold short, or why they bought.
Who has to file a 13F
An investment manager files Form 13F with the US Securities and Exchange Commission (SEC) when it manages at least $100 million in certain US-listed securities.
That covers hedge funds, pension funds, banks, insurers and large family offices. The filing is due within 45 days after each quarter ends.
Source: SEC, Form 13F frequently asked questions, on sec.gov.
What you can learn from one
- What the fund held. Each line names a security, the number of shares and the value at quarter end.
- How big each position was. Compare one line to the total to see where the fund put most of its money.
- What changed. Put two quarters side by side. New lines are new positions. Missing lines were sold.
Four blind spots
| Blind spot | What it means for you |
|---|---|
| It is old on arrival | The list can be up to 45 days old when it appears. The fund may have sold since. |
| Long positions only | Short sales are not on it. A long position may be one half of a hedged pair. |
| US-listed securities only | Most bonds, cash and most stocks listed outside the US are not on it. |
| No reasons | A filing says what the fund held. It never says why. |
How to use it well
- Check the filing date first. Then ask what may have changed since.
- Compare at least two quarters before you read a trend into it.
- Treat it as one input. Check the company's own filings and the price before you decide.
How Lumen shows 13F data
Lumen shows fund holdings as filed with the SEC, with the filing date on every list. If a list is old, you can see that before you read it.