Institutional ownership
What is a 13F filing?
Updated
A Form 13F is the quarterly report through which large institutional investment managers disclose their U.S. equity holdings. Any manager exercising investment discretion over $100 million or more in “13(f) securities,” chiefly U.S. exchange-traded stocks plus certain options and convertibles, must file within 45 days of each calendar quarter’s end. It is the reason the world knows what Berkshire Hathaway, Bridgewater, and thousands of quieter funds own.
What a 13F shows, and what it hides
Each filing lists positions by issuer: share count and market value as of quarter end. That is genuinely useful. Aggregated across managers, it reveals which institutions are accumulating a stock and which are heading for the exit. But the blind spots matter as much as the data. 13Fs show long positions only: no short positions, no bonds, generally no cash, and nothing that trades only on a foreign exchange. The 45-day lag means a position may be gone by the time you read about it. And the $100 million threshold, unchanged since the rule’s adoption in the late 1970s, means smaller managers never appear at all.
Where the rule came from
Congress created the 13(f) regime in 1975, after institutional trading had grown large enough that lawmakers wanted a public record of what the big managers held; the SEC’s implementing rule took effect in 1978, and the $100 million threshold has never been raised. A 2020 proposal to lift it to $3.5 billion drew heavy opposition and was abandoned. Filings have been electronic and structured for years, so the data is machine-readable the moment it hits EDGAR. Separately, 13F filers must now also report their say-on-pay proxy votes annually on Form N-PX, extending the transparency regime from holdings to voting.
Confidential treatment
The rule allows a manager to request confidential treatment for positions still being accumulated, delaying their disclosure past the normal deadline and revealing them only in a later amendment. Berkshire Hathaway has used this repeatedly while building large stakes, and the position appears retroactively once the request lapses. When a major manager’s filing looks unusually thin, a confidential-treatment request is often the explanation, so treat any single quarter’s snapshot as provisional until amendments land.
Reading 13Fs well
The value is in deltas and aggregates, not single filings. Quarter-over-quarter changes reveal accumulation and distribution; concentration shows conviction; and the same stock appearing as a new position across many respected managers is worth noticing. Scrutar assembles filings into an ownership picture per company: see who holds Apple or NVIDIA, and browse the institutional ownership overview for market-wide activity.
One more caveat: 13F value figures are quarter-end snapshots, so a rising stock inflates a “position increase” that involved no buying at all. Always check share counts, not just dollar values.
Where 13Fs fit
Alongside Schedules 13D and 13G, which trigger on 5% stakes in a single company, the 13F is the panoramic view: everything a large manager owns, four times a year, 45 days late. Used with its limits in mind, it remains one of the richest free datasets in markets.