13F Filing Explained: Who Must File, the $100M Threshold, and 13F-HR vs 13F-NT

Who must file a 13F

Form 13F is filed by institutional investment managers — not only funds. A manager is any person or institution that exercises investment discretion over 13F securities: asset managers, hedge funds, bank trust departments, insurance companies, pension sponsors, and even the treasury of a operating company. When you read that “Berkshire Hathaway filed a 13F”, the filer is technically the manager entity (Berkshire Hathaway Inc. in its capacity as investment manager for the insurance subsidiaries).

One manager, one filing — even if the discretion is spread over dozens of funds and accounts. That is why a single 13F row set can mix mutual funds, hedge fund sleeves and proprietary accounts into one portfolio table.

The $100 million threshold, counted correctly

A manager must file once it has investment discretion over at least $100 million of “13F securities”. The test is narrower than it sounds: only exchange-traded and Nasdaq quoted stocks, call and put options, and certain convertible securities count. Cash, US Treasuries, most bonds, private placements and non-US listings do not. A fund with $2 billion under management but 95% in bonds and foreign shares may not have to file at all.

The threshold is tested on the last trading day of each year (the “freeze date”). Pass it once, and you file every quarter of the following year — even if assets shrink. This is one reason the population of filers is sticky: our tracker follows 98 managers across 20 filing quarters, and the roster changes only at the margins each January.

13F-HR vs 13F-NT: the two forms that confuse everyone

13F-HR (Holdings Report) is the form everyone analyzes: the quarterly table of holdings, each row with a security name, CUSIP, share count, and the manager's own market value. Every quarter's table covers positions as of the last trading day of that quarter. A correction is filed as 13F-HR/A (amendment), which is why you occasionally see a quarter's numbers revised months later.

13F-NT (Notice) is filed by a manager that holds no reportable positions itself, because they all appear on another manager's 13F-HR. The classic setup: a fund adviser hands discretion to a sub-adviser or an affiliated manager, who files the HR. The NT simply says “look at them, not me.” Other large managers (big banks, for instance) file an HR that is essentially an aggregate of client positions they administer — the so-called data-dealer filings. Copying those numbers as if they were one investor's bets is a classic 13F mistake.

How the rules shape the data on this site

• One manager = one portfolio view. We track filings per manager entity, so a fund page shows the whole discretionary book, not one product among many.
• Only long US equities (mostly). The HR table contains long positions in 13F securities — see our deep dive on what 13F cannot show.
• Value is self-reported. The value_usd column uses each manager's own valuation, which makes cross-fund comparisons approximate.
• Quarterly, 45 days late. Every list on this site is a snapshot of a quarter that ended at least 45 days ago.