> ## Content Index > Fetch the complete content index at: https://www.bullished.co/llms.txt > Use this file to discover other available public pages before exploring further. # 13F Filing Deadline: What Big Funds' Holdings Do And Do Not Show - URL: https://www.bullished.co/learn/13f-filing-deadline-what-it-shows/ - Published: 2026-11-05T13:28:12.000Z - Updated: 2026-11-05T13:28:12.000Z - Description: A 13F is a delayed, partial snapshot of a big fund's long positions. Here is what it leaves out and which faster filings fill the gap. - Author: Matteo Parrino - Tags: Learn, #learn Key takeaways - A 13F is the quarterly report in which large institutional investment managers list certain holdings they controlled on the last day of a quarter. - It is a delayed snapshot: it arrives weeks after the quarter ends, so it shows where a fund stood, not where it stands now. - It leaves out a lot, including short positions, so it is a partial picture of a fund's real exposure. - Faster filings, such as insider Form 4 reports and ownership filings for stakes crossing 5%, often show moves while they are happening. ## When 13F filings are due and what they cover 13F filings for the September quarter are due in mid-November, which is why this period is called 13F season. The SEC sets the deadline as a set number of days after quarter-end, so the same window repeats every quarter. You can confirm the exact date and read any filing on [EDGAR](https://www.sec.gov/edgar/search/?ref=bullished.co), the SEC's public database. The filer is an institutional investment manager above a size threshold set by the SEC. That covers many mutual fund firms, hedge funds, banks and insurers. For the exact threshold, check the SEC's own materials, since it is a rule that can change. What the report covers is a list of positions in specific securities, mainly US-listed stocks, held on the quarter's last day. It shows the issuer, the number of shares and the value on that date. It does not show what the manager did in between. ## What a 13F leaves out The first gap is time. A position bought and sold inside the quarter never appears. A position that changed sharply after quarter-end is not visible until the next report. The second gap is direction. A 13F is a list of long holdings, so it does not show a fund's short positions. A fund that appears to own a stock could be hedged against it elsewhere, and the filing will not tell you. The third gap is scope. The report covers a defined list of securities, not everything a fund owns. Much of a portfolio, such as many bonds or non-US shares, may not be in it. The fourth gap is intent. A holding says nothing about why the manager owns it, or whether it is a core bet or a small piece of a larger strategy. ## Faster disclosures: Berkshire's Sirius XM Form 4 When an insider or large holder trades, a Form 4 reports it on a much shorter clock than a 13F. A Form 4 is the report insiders and certain large holders file after trading. A recent case shows the contrast. [Berkshire and Buffett bought 924,281 Sirius XM shares](https://www.bullished.co/berkshire-and-buffett-buy-924-281-more-sirius-xm-shares-in-three-days-bf12bade/) over three days, at an average $29.10 a share, or $26.9 million in all. The group began Friday with 743,965 shares bought at a weighted average of $28.89, then added 66,968 shares at $29.47, and on Tuesday bought 113,348 more at $30.23. After those purchases the group reports 125,731,398 Sirius XM shares. A quarterly 13F would show that position only as of a quarter-end date. The Form 4 let readers see it build trade by trade. ## Stake crossing 5%: Perceptive and SK Hynix Anyone who passes 5% of a company's voting shares must file an ownership disclosure. A Schedule 13D is the activist-style version, with more detail on purpose. A Schedule 13G is the shorter passive version. Amendments follow when the stake changes. Both also record exits below 5%. Perceptive shows the exit side. [Perceptive Advisors sold 5,538,839 Nautilus shares](https://www.bullished.co/perceptive-advisors-sold-5-5-million-nautilus-shares-and-slips-below-a-5-stake-3fd93416/) in 16 transactions and now holds 4,944,512 shares, or 3.9% of the company. The sales ran from July 28 to October 26\. The biggest single-day sale was 885,976 shares, and prices ranged from $1.3081 to $3.1154 a share. A 13F would have shown only the quarter-end snapshot, not that path. SK Hynix shows the entry side. [SK hynix reported a 9.1% stake in Penguin Solutions](https://www.bullished.co/sk-hynix-reports-9-1-stake-in-penguin-solutions-with-a-board-seat-attached-4d0cbd46/) through a $377,162,666 cash preferred-stock purchase. The filing counts 6,096,103 common shares today, and the preferred carries a 6% annual cumulative payout and a conversion price of $32.80784\. It also attaches director nomination rights, which no holdings list would reveal. ## How to use 13F data carefully Treat a 13F as a dated snapshot. Check the quarter-end date first, then ask what could have changed since. Compare it with faster filings. If a fund's name appears in a Form 4 or a 13D/13G, those show newer activity and often more context, such as deal terms. Do not read a fund's holdings as a recommendation or a prediction. A position can be hedged, small or already sold. For more on how filings work, see [Investor.gov](https://www.investor.gov/?ref=bullished.co) and [FINRA's investor pages](https://www.finra.org/investors?ref=bullished.co). ## Frequently asked questions ### When are 13F filings due? They are due a set number of days after each quarter ends, which puts the September-quarter deadline in mid-November. Confirm the exact date on the SEC's site. ### Does a 13F show short positions? No. It lists long holdings of covered securities on the last day of the quarter, so shorts and many hedges are not visible. ### Who has to file a 13F? Institutional investment managers above the SEC's size threshold, which can include fund firms, banks and insurers. Check the SEC's current rules for the exact test. More plain-English guides to filings and market events: [Bullished Learn →](https://www.bullished.co/learn/) ### Sources - [EDGAR full-text search](https://www.sec.gov/edgar/search/?ref=bullished.co) — U.S. Securities and Exchange Commission - [Investor.gov](https://www.investor.gov/?ref=bullished.co) — U.S. Securities and Exchange Commission - [FINRA for investors](https://www.finra.org/investors?ref=bullished.co) — FINRA - [Berkshire And Buffett Buy 924,281 More Sirius XM Shares In Three Days](https://www.bullished.co/berkshire-and-buffett-buy-924-281-more-sirius-xm-shares-in-three-days-bf12bade/) — Bullished - [Perceptive Advisors Sold 5.5 Million Nautilus Shares And Slips Below A 5% Stake](https://www.bullished.co/perceptive-advisors-sold-5-5-million-nautilus-shares-and-slips-below-a-5-stake-3fd93416/) — Bullished - [SK Hynix Reports 9.1% Stake In Penguin Solutions, With A Board Seat Attached](https://www.bullished.co/sk-hynix-reports-9-1-stake-in-penguin-solutions-with-a-board-seat-attached-4d0cbd46/) — Bullished *Bullished Learn guides explain how filings and markets work. They are education, not investment advice: nothing here is a recommendation to buy or sell any security.*