13F Securities: Definition, Filing Rules, and Confidentiality

Section 13(f) securities are equity instruments — exchange-listed stocks, NASDAQ-quoted shares, certain options and warrants, closed-end fund shares, and some convertible debt — that large institutional investment managers must disclose to the Securities and Exchange Commission every quarter. Any manager with investment discretion over at least $100 million of these holdings has to file Form 13F within 45 days of quarter-end, and the filings are public.¹

What Qualifies as a 13F Security

The SEC defines a section 13(f) security as an equity security of a class admitted to trading on a national securities exchange or quoted on the automated quotation system of a registered securities association.² Four categories cover most of what actually shows up on filings:

Common and preferred shares listed on the NYSE, NASDAQ, and other national exchanges.
Certain listed equity options and warrants tied to exchange-traded stocks.
Shares of closed-end investment companies that trade on an exchange.
Convertible debt securities that can be converted into equity shares, though this category is narrower than the others.

Shares of open-end investment companies — ordinary mutual funds — are not section 13(f) securities and do not appear on Form 13F.³

The SEC publishes an Official List of Section 13(f) Securities and updates it quarterly to reflect new listings, delistings, mergers, and other corporate events.⁴ Check your portfolio against the current version before filing. If a security isn’t on the list, it generally doesn’t belong on the form.

Who Has to Report

The filing obligation falls on institutional investment managers. That term reaches any entity that buys or sells securities for its own account, as well as any person or entity that makes investment decisions for someone else’s account.¹ Banks, insurance companies, broker-dealers, pension funds, and registered investment advisers commonly qualify. So do corporations that manage their own investment portfolios internally.

The trigger is $100 million in section 13(f) securities, measured by aggregate fair market value on the last trading day of any month during a calendar year.² Investment discretion means having the power to decide which securities get bought or sold for the accounts under management, and a manager is also deemed to exercise discretion over accounts controlled by anyone under the manager’s control.

One narrow carve-out: if you control the issuer of a class of 13(f) securities, those securities aren’t counted toward your $100 million threshold and aren’t reported, unless you separately manage other accounts that meet the threshold on their own.²

When Reporting Starts and Continues

Once a manager’s section 13(f) holdings hit $100 million on the last trading day of any month, the clock starts. The first required filing covers the fourth quarter of that calendar year. The manager then files for all four quarters of the following calendar year, even if the portfolio’s value drops below $100 million in the meantime.¹

After that first cycle, the obligation continues year to year as long as the manager keeps meeting the threshold during any month of a given calendar year. Crossing the line for a single day in a single month locks in filings through the end of the following year’s third quarter.¹ Assuming you can skip a quarter because the portfolio dipped is a common way to end up in an enforcement action.

What Form 13F Discloses

For each reportable security, Form 13F asks for the following as of the last day of the calendar quarter:⁵

The issuer’s name.
The title and class of the security, such as common stock, preferred stock, or put options.
The CUSIP number, a nine-character alphanumeric code that uniquely identifies each security across all financial institutions.
The number of shares or principal amount held.
The aggregate fair market value, based on the closing price on the last trading day of the quarter.

Dollar values are rounded to the nearest dollar. Managers may also include a Financial Instrument Global Identifier (FIGI) for each security, though the CUSIP remains mandatory.¹

For each position, the manager also indicates whether it holds sole or shared voting authority and sole or shared investment discretion. Those columns let regulators and the public see not just what is owned, but how much control the manager actually exercises.

How and When to File

All Form 13F reports go through the SEC’s Electronic Data Gathering, Analysis, and Retrieval system (EDGAR).⁶ Filings are submitted in XML and must conform to the SEC’s form-specific schema.⁷

The deadline is 45 calendar days after the end of each quarter. Quarters close on March 31, June 30, September 30, and December 31, so a fourth-quarter report is due by February 14 of the following year.²

Not every filer submits the same form type. Three variations exist:

The 13F-HR Holdings Report, filed when the manager lists all of its reportable securities on its own form. This is the standard filing.
The 13F-HR Combination Report, filed when some holdings appear on the manager’s own form and the rest are reported on another manager’s form.
The 13F-NT Notice, filed when all of the manager’s holdings are reported on another manager’s form. The notice contains only a cover page identifying which other manager is doing the reporting.

The notice scenario typically arises in parent-subsidiary structures where a parent reports on behalf of its subsidiaries.¹ Once EDGAR accepts any of these filings, the information becomes a public record anyone can access for free through the SEC’s filing search.

One boundary to note: Form 13F covers long positions only. Short positions are reported under a separate regime, Rule 13f-2 and Form SHO, which requires monthly filings within 14 calendar days after month-end when a manager’s short position in a given stock meets thresholds such as a monthly average gross short position of at least $10 million or at least 2.5 percent of the outstanding shares.⁸ A 13F filing alone will never show the full picture of a manager’s market exposure.

Keeping Some Holdings Confidential

A manager that does not want certain holdings made public immediately can request confidential treatment under Rule 24b-2. This most often comes up while a manager is still building or unwinding a position and premature disclosure would undermine the strategy. The request is filed electronically alongside the regular 13F submission, and the public version notes that certain holdings have been omitted and filed separately with the Commission.⁹

Confidential treatment isn’t automatic. The manager must explain its investment strategy, demonstrate why public disclosure would prematurely reveal that strategy, and show that the information is actually kept private in the ordinary course of business. Each holding must be discussed individually unless a group of holdings shares substantially identical facts and legal analysis.⁹ The SEC expects a specific, supported argument tied to the time period requested, not a blanket demand for indefinite secrecy.¹⁰

A streamlined path exists for open risk arbitrage positions where no prior confidential treatment request has been made. Holdings belonging to natural persons, estates, or non-business trusts receive automatic protection under the statute and don’t require the same detailed analysis.⁹

Correcting a Filing

When a previously filed Form 13F contains errors or needs updating, the manager files an amendment. An amendment must either restate the entire report or add holdings entries that weren’t included in the original public filing. Each amendment requires a complete cover page, and where applicable a summary page and an updated information table.⁹

Amendments are also required when confidential treatment expires or is denied. In that case, the manager files an amendment disclosing the previously hidden holdings within six business days. The cover page must include a legend identifying the original filing date and the date confidential treatment ended.⁹ Missing that six-day window is treated as a separate compliance failure.

What Happens If You Don’t File

The SEC pursues 13F violations. In September 2024, the agency charged 11 institutional investment managers with failing to file required Forms 13F. Nine of them paid a combined total of more than $3.4 million in civil penalties, with individual amounts ranging from $175,000 to $725,000.¹¹

The two firms that avoided monetary penalties had self-reported their violations and cooperated with the investigation.¹¹ If you discover a missed filing, contact counsel and consider self-reporting promptly rather than waiting to see whether the SEC notices.

1
Securities and Exchange Commission. Frequently Asked Questions About Form 13F
2
eCFR. 17 CFR 240.13f-1 – Reporting by Institutional Investment Managers
3
Investor.gov. Form 13F – Reports Filed by Institutional Investment Managers
4
Securities and Exchange Commission. Official List of Section 13(f) Securities
5
Office of the Law Revision Counsel. 15 USC 78m – Periodical and Other Reports
6
Securities and Exchange Commission. Search Filings
7
Securities and Exchange Commission. Technical Specifications
8
Securities and Exchange Commission. Final Rules – Enhancing Short Sale Disclosure
9
Securities and Exchange Commission. Form 13F – Information Required of Institutional Investment Managers
10
Securities and Exchange Commission. Section 13(f) Confidential Treatment Requests
11
Securities and Exchange Commission. SEC Charges 11 Institutional Investment Managers with Failing to Report Certain Securities Holdings