Every quarter, the largest investment managers in the US file a list of what they hold. Those 13F reports are widely read, because they are the closest the public gets to seeing inside other investors' portfolios. They are also widely overread. A 13F is a partial, delayed snapshot of one day, and it leaves out much of what a manager actually does.
Who files
Form 13F must be filed by every institutional investment manager that exercises investment discretion over $100 million or more in "Section 13(f) securities". That includes hedge funds, mutual fund managers, pension funds, banks, insurers and family offices that manage enough money.
The filer is the manager, not a fund. A manager running dozens of funds files one report covering all of them. When several managers share discretion over the same holdings, one may report them and the others file a short notice saying so (a 13F-NT).
When
Within 45 days after the end of each calendar quarter. The holdings are as of the last day of the quarter. A report filed on the deadline describes a portfolio as it stood six weeks earlier.
What one line shows
Each holding is one line in an information table:
- Name of issuer and title of class, such as common stock, a share class, or a note;
- CUSIP, the nine-character id of the security;
- value, at the end of the quarter. Since 2023 this is in dollars; earlier reports gave it in thousands of dollars, so check the date before comparing old and new figures;
- shares or principal amount, and which of the two it is;
- put or call, if the line is a listed option;
- investment discretion: sole, shared with another manager, or other;
- other managers included in the line;
- voting authority: how many shares the manager can vote alone, shares with others, or cannot vote.
What it does not show
This is the longer list, and the more important one.
- Short positions. A 13F lists long positions only. A manager can be short a stock in a size that more than offsets the long position shown, and the 13F will not say.
- Most of the portfolio, for many managers. Only Section 13(f) securities are reported: mostly US exchange-listed shares, plus certain listed options, convertible bonds and exchange-traded funds. Cash, most bonds, shares listed only outside the US, private companies, real estate, commodities and most derivatives are absent.
- What happened during the quarter. A stock bought in week two and sold in week ten never appears. A position that looks unchanged may have been sold and rebought.
- When and at what price. The report gives a value at the quarter end, not the dates or prices of trades.
- Which fund holds it. The report covers the whole manager. Mutual funds report their own holdings separately, on Form N-PORT.
- Small positions. A holding of fewer than 10,000 shares and less than $200,000 in value may be left off.
- Positions under confidential treatment. A manager can ask the SEC to delay disclosure of a position, for example while it is still building it. Approved positions appear later in an amended report.
- Why. Nothing in a 13F explains a decision.
The trap in options
Listed put and call options are reported with the number of underlying shares and the value of those shares, not the value of the options. A put line for a large number of shares looks, in a quick total, like a large long holding, when it may be a position that gains if the stock falls, or a hedge against the manager's long position. Read the put/call column before adding anything up.
Reading the changes
The most common use of 13Fs is to compare one quarter with the last: new positions, positions closed, positions increased or cut. Some cautions:
- The changes are between two snapshots, six weeks stale and three months apart. By the time you see a new position, the manager may already have sold it.
- Value changes are not trades. A holding's value can double because the share price rose, with no shares bought. Compare share counts, not values.
- Size matters relative to the portfolio. A position that is 0.1% of a large manager's reported holdings is a rounding error to them, however large the dollar figure.
- Quant and index managers hold thousands of positions for reasons that have nothing to do with a view on any single company.
- Large holders also file elsewhere. A manager that crosses 5% of a company's voting shares files a Schedule 13D or 13G, often much sooner than its next 13F. Those filings are more timely and, in the case of a 13D, say what the holder intends.
How Listed shows 13F data
- Fund pages show each manager's latest quarter as filed: issuer name, class, CUSIP, value and shares, with the change from the quarter before.
- Source and delay. Holdings come from the SEC's quarterly Form 13F data sets, which follow the filing deadlines. A fund page can be up to three months behind the filings themselves, on top of the 45 days a manager has to file. Each page says which quarter and which data set it shows.
- No link to company pages. CUSIPs are licensed identifiers and the full list is not public. Listed keeps no CUSIP master, so it does not map holdings to company pages. The issuer name is as the manager filed it.
- No prices. Values are as the manager reported them at the quarter end. Listed does not revalue holdings at today's prices, because it shows no prices at all.
A fair summary
A 13F tells you that a manager held at least this many shares of a listed security on one day, at the end of a quarter, and nothing about why, for how long, or what else they held against it. That is useful information. It is a starting point for reading, not a list of anyone's best ideas.