What is Form 13F?
Quarterly Fund Holdings Explained

Any institutional investment manager controlling $100 million or more in Section 13(f) securities — exchange-listed equities, options, convertibles, and certain ETFs — must file Form 13F-HR quarterly with the SEC.

The filing deadline is 45 days after each calendar quarter end: roughly February 14, May 15, August 14, and November 14. The filing reflects holdings as of the last day of the quarter — December 31, March 31, June 30, and September 30.

"Institutional investment manager" is broad: it covers hedge funds, mutual funds, pension funds, insurance companies, banks, broker-dealers, and any entity that invests on behalf of others. Individual investors with $100M+ in a personal account also qualify. There are over 10,000 active 13F filers as of 2025.

The missing short positions are the most important blind spot. A fund that shows a massive long position in a stock may simultaneously be short a related name — the 13F only tells you half the story. A fund that looks bullish on Tech in aggregate via long positions could be running a pairs trade where they're net short the sector.

A 13F filed on February 14 reflects December 31 positions — holdings that are up to 6 weeks stale by the time the market sees them. A fund may have entered, grown, and partially exited a position before any public disclosure occurs.

For rapidly evolving situations — earnings plays, M&A rumors, macro-driven names — 13F data is historical, not a current signal. Use it as context for long-term conviction, not as a real-time trade trigger.

Confidential treatment: funds can request confidential treatment for positions they're still accumulating. These positions disappear from the public 13F and appear months or years later as historical data. When a sudden large position appears in a 13F that wasn't in prior filings, it may have been accumulated under confidential treatment — meaning the fund already has a full position and the market is learning about it late.

The raw position size isn't as useful as the change from the prior quarter. A fund that added significantly last quarter — especially one with a strong long-term track record — is a signal worth tracking.

New positions from top funds are particularly interesting — they represent fresh conviction from the fund's research process, not a position being managed. When a name like Druckenmiller or Ackman initiates a new position, it typically drives copycat inflows within days of the 13F filing.

BullishAgent ingests 13F-HR filings from EDGAR as they are filed each quarter. Each filing is parsed for position-level holdings — ticker, share count, value, and voting authority — and compared against the prior quarter's filing for the same fund to compute QoQ changes (NEW, INCREASED, DECREASED, EXITED).

Known legendary investors (Buffett, Ackman, Druckenmiller, Icahn, Loeb, Dalio, and others) are tracked separately and flagged on each stock's page and in the Fund Holdings section. New positions and large increases from these funds appear in The Open morning brief on 13F filing days — roughly February 14, May 15, August 14, and November 14 each year.

Remember the 45-day lag: by the time a 13F appears, the fund may have already moved. Use the data as confirmation of long-term institutional conviction, not as a timing signal.

While 13F covers hedge funds and institutional managers quarterly, Form N-PORT covers a completely different universe: SEC-registered investment companies — mutual funds, money market funds, and closed-end funds — filing every month. It is the highest-frequency institutional holdings data available from EDGAR.

N-PORT is due within 60 days of the period end date. So January 2026 positions (ending Jan 31) are due by March 31. That means holdings can be 60–90 days stale — actually older than 13F in some cases — but the monthly cadence means you get more frequent updates than the quarterly 13F cycle.

N-PORT vs 13F — which to use: they cover different universes. A Fidelity or Vanguard mutual fund files N-PORT monthly; Fidelity's institutional advisory arm also files 13F quarterly — under a different CIK. Hedge funds and activists only appear in 13F. For a complete picture of institutional conviction in a stock, you need both.

The signal to watch: when a large mutual fund (total assets $10B+) initiates a brand-new position and immediately allocates 2%+ of the fund, that represents months of research and a high-conviction decision. New positions from large registered funds are one of the strongest N-PORT signals — they cannot trade as tactically as a hedge fund, so every new initiation is deliberate. Track these on the Monthly Holdings page.