SEC Form 13F: Institutional Holdings Report Explained

What Is a Form 13F Filing?

SEC Form 13F is a quarterly disclosure required of institutional investment managers — hedge funds, mutual funds, pension plans, banks, insurance companies, and registered investment advisers — that exercise discretion over $100 million or more in Section 13(f) securities. The filing must be submitted within 45 days of the end of each calendar quarter.

The report lists every reportable holding: the issuer name, ticker, CUSIP, share count, market value, share type (common shares vs. principal amount), put/call designation for options, investment discretion, voting authority, and any other managers who share discretion over the position. For the largest filers — Vanguard, BlackRock, State Street — a single 13F can contain more than 10,000 individual holdings.

Form 13F Variants

• 13F-HR (Holdings Report): The full quarterly report with cover page, summary page, and complete information table of holdings. This is the document most investors mean when they say "13F."
• 13F-NT (Notice Report): A notice-only filing used when all of a manager's reportable holdings are already disclosed by another manager (typically a parent or subsidiary). It contains no information table.
• 13F-HR/A and 13F-NT/A: Amendments to previously filed holdings or notice reports. Amendments often correct misreported share counts, add missed positions, or update share class designations.

Who Must File a 13F?

An institutional investment manager must file a 13F if it exercises investment discretion over $100 million or more in Section 13(f) securities — a list of equity securities and certain options published quarterly by the SEC. Once a manager crosses the threshold, it must file for the fourth quarter of that year and for each quarter of the following year, even if assets later fall below $100 million.

Common 13F filers include:

• Hedge funds: Tiger Global, Pershing Square, Third Point, Coatue, and thousands of smaller funds disclose long equity positions each quarter.
• Mutual funds and ETF sponsors: Vanguard, BlackRock, Fidelity, and Capital Group file aggregate disclosures across their fund families.
• Pension and endowment funds: CalPERS, Yale Endowment, and corporate pension plans report their externally managed and direct holdings.
• Bank trust departments and insurance companies: Trust holdings on behalf of clients and general account portfolios are reportable.

What a 13F Reveals (and What It Doesn't)

The information table in a 13F-HR is the core of the filing. Each row tells you exactly what an institution owned at quarter-end, the dollar value of the position, and whether the manager has sole, shared, or no voting authority over the shares. By comparing two consecutive quarters, you can see new positions, increased stakes, reduced positions, and complete exits.

What 13F filings do not disclose is just as important:

• Short positions and most derivatives: 13F is a long-only disclosure. A fund's net exposure can look very different from its reported 13F holdings.
• Foreign securities: Holdings outside the Section 13(f) list — including most non-US stocks — are not reported.
• Cash and bonds: Cash positions, sovereign debt, and most corporate bonds fall outside the reportable universe.
• Intraquarter activity: A 13F is a quarter-end snapshot. A position that was opened and closed within the quarter never appears.

Why 13F Filings Move Markets

Institutional ownership changes are one of the most-watched indicators in equity markets. When a respected fund initiates a large new position, copy-trading and momentum flows often follow. When several institutions exit the same name in the same quarter, it can signal a deteriorating thesis. The 45-day reporting lag means 13F data is never current, but the patterns it reveals — concentration, accumulation, exits, sector rotation — remain among the most reliable institutional intelligence available to public investors.

13F data is also the baseline that gives Schedule 13D and 13G filings their meaning. A 13D announcing a 6% activist stake is far more impactful when 13F data shows the activist quietly building from 1% over the prior two quarters.

How NexusAlert Reads 13F Filings

NexusAlert parses every 13F-HR, 13F-NT, and amendment as it lands on EDGAR. The AI extracts the top holdings, total portfolio value, new positions, exited positions, and the largest position changes from the prior quarter. For any ticker, you can see the full institutional holder list, quarterly value trends, and a unified Institutional Activity view that overlays 13F holdings against any 13D and 13G filings on the same chart — so the long-term ownership baseline and the 5%-threshold events are visible side by side.

Dive deeper on the Institutional Ownership feature page to see how 13F holdings, 13D activism, and 13G passive stakes are unified on one timeline.

Related Filing Types