Who has to file a 13F?
TL;DR
Any institutional investment manager that exercises investment discretion over $100 million or more in Section 13(f) securities must file Form 13F with the SEC within 45 days of each quarter-end (Rule 13f-1). That is a low bar — it captures hedge funds, mutual fund advisers, pension funds, banks, insurers, and RIAs alike, so well over 5,000 managers file every quarter. An individual trading their own account below $100M does not file one.
A 13F must be filed by any institutional investment manager with over $100 million in US-listed equity assets under its investment discretion. It is a filing requirement triggered by size, not by fund type.
Who counts as an “institutional investment manager”?
The term comes from Section 13(f) of the Securities Exchange Act of 1934. It is broader than “hedge fund.” It covers any entity that invests in securities for its own account, plus anyone exercising investment discretion over someone else’s account, including:
- Hedge funds and their management companies (Berkshire, Pershing Square, Scion, Baupost)
- Mutual fund and ETF advisers
- Pension funds and endowments
- Banks, trust companies, and insurance companies
- Registered investment advisers (RIAs)
This is why HoldLens can track 30+ superinvestors at all: they are legally required to publish their long US-equity book four times a year.
How the $100 million threshold actually works
The trigger is not your assets on December 31. Under Rule 13f-1, a manager must file if it held $100 million or more in Section 13(f) securities on the last trading day of any month during a calendar year. Crossing it once means:
- You file a 13F for that year’s fourth quarter, and
- You keep filing for the first three quarters of the following year — even if you drop back below $100M.
Only Section 13(f) securities count toward the $100M — not bonds, not cash, not private holdings, not non-US stocks. The SEC publishes the Official List of Section 13(f) Securities each quarter so managers know exactly what qualifies.
When is it due?
Within 45 days after each calendar quarter-end — the same deadlines that create the famous 45-day lag:
- Q1 (Jan–Mar) → due May 15
- Q2 (Apr–Jun) → due August 14
- Q3 (Jul–Sep) → due November 14
- Q4 (Oct–Dec) → due February 14
More on why that gap matters: the 45-day lag explained.
13F-HR, 13F-NT, and amendments
A filer’s obligation can show up under different form types:
- 13F-HR — the holdings report; the actual position list.
- 13F-NT — a notice filing, used when the manager’s holdings are reported on another manager’s 13F-HR (common with sub-advisers).
- 13F-HR/A — an amendment correcting or adding to a prior holdings report.
Confidential treatment — the legal way to hide a position
A filer can request confidential treatment to delay disclosing specific positions, typically while it is still accumulating a stake and wants to avoid being front-run. The SEC reviews these requests; Berkshire Hathaway has used the mechanism more than once. Once granted time expires (or the request is denied), the position appears in an amended filing.
Who does not file a 13F?
- Individuals managing their own money below $100M — the vast majority of retail investors.
- Managers whose 13(f) holdings never cross $100M on a month-end.
- Funds holding only non-US equities, bonds, crypto, or private assets — none of those are 13(f) securities.
- Short-only or derivatives-only books — 13Fs disclose long equity positions, so a manager with no reportable long 13(f) securities has nothing to report.
Our view
The $100 million threshold is the single most underrated fact about 13F data. It is extraordinarily low for an institutional bar set in 1978 and never indexed to inflation, so the filer pool is enormous and noisy — thousands of pension sub-advisers and index-hugging RIAs file the exact same form as Buffett. The signal is not “an institution filed,” it is which institution, and how concentrated and persistent its book is.
That is why HoldLens does not treat every 13F filer equally. We curate a short list of managers with demonstrated skill and conviction, then score each holding by portfolio weight and multi-quarter trend — separating the handful of filings worth reading from the 5,000+ that are mostly index padding.
Foundational reading on securities analysis
Now that you know who has to disclose, the books below are where the disciplined filers learned to allocate — Graham, Lynch, Munger.
Bookshop.org affiliate links — HoldLens earns a 10% commission if you buy, at no extra cost to you. Bookshop.org is the indie-bookseller consortium that supports local bookstores. These are the books we actually recommend. Always do your own research.
Not investment advice. Filing requirements summarized from SEC Rule 13f-1 and the SEC 13F FAQ; verify against the primary sources linked above. See methodology for how we parse and score every filing.
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See who actually files, live on HoldLens
Live 13F tracker — every quarterly filing from 30+ tracked managers, scored on the −100..+100 ConvictionScore. Manager rankings, new positions. Related explainers: what is a 13F, how to read one, the 45-day lag.