The SEC's List of Section 13(f) Securities, Explained

The SEC's list of Section 13(f) securities is the published roster of securities that count toward Form 13F reporting: if a security is not on it, a manager does not report holding it, no matter how large the position. The SEC's Division of Investment Management publishes an updated list every quarter, and it is the actual test institutional managers use to decide what goes into their next 13F, not a general description of "big stocks." This guide covers what the list includes, how it changes each quarter, and what that means when you are reading 13F holdings data as a source of institutional ownership.

What makes a security a "Section 13(f) security"

Under Rule 13f-1(c) of the Securities Exchange Act of 1934, a "Section 13(f) security" is any security that appears on the SEC's current Official List. The list itself, in turn, is built around the kinds of securities Congress had in mind when it wrote Section 13(f): mainly equity securities that trade on a national securities exchange or on Nasdaq.

In practice, the list covers:

• Equity securities (common and preferred stock) listed on a national exchange or Nasdaq
• Certain equity options and warrants
• Shares of closed end investment companies
• Certain convertible debt securities that convert into a 13(f)-eligible equity

It leaves out:

• Shares of open end mutual funds, which are never Section 13(f) securities
• Most conventional bonds and other non-convertible debt
• Securities that do not trade on an exchange or Nasdaq, even when a security is otherwise widely held

This is why Form 13F was designed as a narrow, standardized disclosure rather than a full balance sheet: the SEC fixed the universe of reportable securities in advance, instead of letting each manager decide what to disclose.

The quarterly Official List

The SEC publishes a new edition of the Official List once each calendar quarter, and the current edition is what managers are expected to rely on when they prepare the Form 13F due 45 days after that quarter ends. Each edition carries a CUSIP, an issuer and class description, and a status column for every covered security, and it is free to download from the SEC's site.

ADDED and DELETED: how the list changes every quarter

Each new edition of the list marks what changed since the last one. A security newly added carries the word ADDED in its status column, meaning it has become a Section 13(f) security since the prior list, usually because it started trading on a qualifying exchange. A security marked DELETED has dropped off the list, usually because it stopped trading, was acquired, or moved to a market the rule does not cover.

This matters for anyone tracking a security across several quarters of 13F data: a CUSIP that stops appearing in holdings rows is not necessarily evidence that every manager sold it. It can simply mean the security left the Official List, so it is no longer reportable even for managers still holding it.

Why this makes 13F data narrower than a full portfolio

The most common misreading of 13F data is treating it as a complete picture of what a manager owns. It is not. A manager with $5 billion in assets under management might hold a mix of listed equities, convertible notes, corporate bonds, and mutual fund shares, and only the first two categories (and only the convertible notes that meet the conversion test) are Section 13(f) securities. The bonds and the fund shares are real holdings that simply never show up in a 13F filing, because they are not on the list at all.

The same logic applies in the other direction: a security can be thinly traded and still be on the Official List if it is listed on a qualifying exchange, so being covered by 13F does not by itself signal that a stock is large or liquid.

For a broader look at what a 13F filing contains when a security is reportable, see our guide to what a 13F filing covers.

How SecFeed's CUSIP data relates to the Official List

It is worth being precise about where SecFeed's own CUSIP data comes from, because it is not the Official List itself. The /v1/mapping/cusip endpoint returns the issuer names and CUSIPs that managers actually wrote into their 13F filings, and the listed companies that match those names. That is a narrower set than the full Official List: it only includes securities that at least one manager has actually reported holding, not every security that was ever eligible to be reported.

curl "https://secfeedapi.com/v1/mapping/cusip?cusip=037833100" \
  -H "Authorization: Bearer YOUR_API_KEY"

[
  {
    "cusip": "037833100",
    "issuerName": "APPLE INC",
    "matches": [
      {"cik": 320193, "name": "Apple Inc.", "ticker": "AAPL", "exchange": "Nasdaq"}
    ]
  }
]

/v1/mapping/cusip is capped at 50 lookups a day per key, which is enough for checking individual securities but not for reconstructing the Official List wholesale. See the CUSIP, CIK and ticker mapping API for the rest of the mapping endpoints, and the full parameter reference for how the lookup behaves on CUSIPs with more than one issuer match.

Working with the list in practice

If you are trying to decide whether a specific security should appear in 13F holdings data at all, the practical check is simpler than reading the rule: query SecFeed's holdings endpoint by CUSIP across a few recent quarters. If managers have reported it recently, it is currently a Section 13(f) security. If it never appears despite a manager plausibly holding it, the more likely explanation is that it is outside the Official List's scope (a bond, a fund share, or an unlisted equity), not that your query is wrong.

from secfeed import Client

sf = Client("YOUR_API_KEY")
rows = sf.holdings_13f(cusip="037833100", period="06-30-2026")
print("reported this quarter" if rows else "not reported this quarter")

Frequently asked questions

Is every stock a Section 13(f) security?

No. Only securities on the SEC's current quarterly Official List qualify, which generally means equity securities trading on a national exchange or Nasdaq, plus certain options, warrants, closed end fund shares, and convertible debt. A stock that trades only over the counter outside those venues may not be on the list.

Why did a security disappear from a manager's 13F holdings?

It can mean the manager sold the position, but it can also mean the security was marked DELETED from the Official List and is no longer reportable even if the manager still holds it. Check the security's status before assuming a sale.

Does 13F data cover bonds a manager holds?

Generally no. Most conventional bonds are not Section 13(f) securities. Certain convertible debt securities can qualify if they convert into a reportable equity, but plain corporate or government bonds are outside 13F reporting entirely.

Where can I find the current Official List?

The SEC's Division of Investment Management publishes it quarterly and makes it free to download from its website. SecFeed's own CUSIP data in /v1/mapping/cusip reflects CUSIPs managers have actually reported, which overlaps with but is narrower than the full Official List.

Are mutual funds included in 13F reporting?

No. Shares of open end mutual funds are explicitly excluded from the definition of a Section 13(f) security, so they never appear in Form 13F holdings data regardless of how large a manager's position is.