- Who files: any institutional investment manager exercising discretion over $100M+ in Section 13(f) securities.
- When: within 45 calendar days of quarter-end — Feb 14, May 15, Aug 14, Nov 14 in a normal year; a weekend or holiday deadline rolls to the next business day.
- What it shows: long positions held on the last day of the quarter — issuer, class, CUSIP, shares, market value, discretion, and voting authority.
- What it never shows: shorts, cash, most bonds, foreign-listed stocks, swaps, or anything traded inside the quarter.
- Scale: 8,857 managers filed for 2026Q2. GetCoattail tracks 147 of them under strict filters, back to 2016Q3.
Who has to file
Section 13(f) of the Securities Exchange Act requires institutional investment managers that exercise investment discretion over $100 million or more in Section 13(f) securities to file Form 13F every calendar quarter. That covers hedge funds, mutual fund companies, pension funds, banks, insurers, endowments, and family offices — not just household names. A manager below the threshold does not appear in 13F data at all, so absence from the filings is not evidence of absence from a stock. Once a manager crosses the threshold in a calendar year, it keeps filing for the rest of that year.
For 2026Q2, 8,857 managers filed market-wide. GetCoattail follows 147 of them — funds that filed in at least 7 of the last 8 quarters, keep options at 5% or less of the portfolio, hold 5 to 150 stocks, concentrate at least 40% in their top 10, overlap at least 60% of holdings quarter to quarter, and run portfolios of $50M or more. The filter exists so that the tracked set is comparable quarter to quarter, instead of a rotating cast.
When: the 45-day clock
The filing deadline is 45 calendar days after the quarter ends. In an ordinary year that means February 14 (Q4), May 15 (Q1), August 14 (Q2), and November 14 (Q3). If the deadline falls on a weekend or federal holiday, it rolls to the next business day — which is why the Q3 2026 deadline is November 16, 2026, a Monday: November 14 is a Saturday. GetCoattail’s Q3 2026 season tracker follows every tracked fund against that deadline.
The clock matters because the positions inside are dated the last day of the quarter, not the filing day. A filing that lands on November 16 describes holdings as of September 30 — 47 days old on arrival, and older by the time you read it. Anything the fund bought or sold in October is invisible. Treat every 13F as a dated photograph, never as a live portfolio.
Anatomy of one row
Each row of the information table describes one position. In plain language:
| Column | What it means | What to watch |
|---|---|---|
| Issuer name | The company or fund whose security is held. | Names can be abbreviated or stale; match on CUSIP, not on spelling. |
| Title of class | Common stock, ETF shares, convertible notes, and so on. | The same issuer can appear on several rows for different classes. |
| CUSIP | The security’s identifier. | This is the join key across quarters and managers. Corporate actions can change it. |
| Value (in thousands) | Market value of the position at quarter-end. | Value moves with price even when shares don’t — compare shares, not just value. |
| Shares / principal amount | How many shares (or how much principal) were held. | Share changes are the closest thing to a trading signal in the form. |
| Investment discretion | Sole, shared, or none. | “Shared” rows can double-count a position across managers if you add filers naively. |
| Voting authority | Sole, shared, or none, per position. | Voting power and economic exposure are different things; the form reports both. |
| Put / call flag | Whether the row is an option position. | An option row is not stock. Its VALUE is the underlying value referenced, not the premium paid, and no strike or expiry is reported. |
Two filing types matter. Form 13F-HR is the holdings report itself. Form 13F-NT is a notice: it says another manager reports these holdings, and contains no positions. If you count NT filers as holders, or add an NT filer’s “holdings” to the reporting manager’s, you double-count. Always resolve notices to the reporting filer before aggregating.
Five things a 13F never shows
1. Short positions. Shorts are not reported and are not netted against longs. A fund that is long $500M of a stock and short $400M of it looks, in 13F, like a $500M bull.
2. Cash and most bonds. Cash, money-market holdings, and most fixed income are outside Section 13(f) coverage. A 13F never sums to a fund’s total assets.
3. Foreign-listed stocks. Only Section 13(f) securities — overwhelmingly U.S.-listed equities, ETFs, and some convertibles and options — appear. A global fund’s non-U.S. book is invisible.
4. Swaps, futures, and OTC derivatives. A fund can carry large economic exposure through instruments that never touch the information table.
5. Anything that happened inside the quarter. A position opened and closed between quarter-ends leaves no trace. The form shows endpoints, not the path.
Reading changes: new, added, reduced, exited
Quarter-over-quarter comparison is where 13Fs earn their keep, and where most misreadings happen. GetCoattail labels each position against the fund’s previous filing as new (not held last quarter), added (shares up), reduced (shares down), or exited (held last quarter, gone now). Three cautions apply to all four labels.
First, compare shares before value. A position’s value can rise 20% because the stock rose 20%; only a share increase means the fund bought more. Second, “new” does not mean first-ever: a fund can exit a stock, wait a quarter, and re-enter, and the re-entry reads as new. Third, weight is relative: a fund whose whole book shrank can show a higher weight in a stock it actually trimmed. Read shares, weight, and the fund’s total together — each fund page on GetCoattail shows all three.
The lag, in calendar terms
Take the current season as the example. The quarter ended September 30, 2026. Funds have until November 16 to file. A fund that sold its entire stake in a stock on October 5 will still show that stake in its Q3 filing, filed in November, and a reader in late November will see a September position as if it were current. That is not a data error; it is how the rule works. The productive use of 13F season is structural research — who accumulates what, where concentration builds, which themes repeat across managers — not tape trading on filing day. For the same reason, this site scores 13F signals from the first close after the filing deadline, never from quarter-end prices no reader could have acted on.
How GetCoattail tracks 13Fs
Every tracked fund gets a page (all 147 managers) with its quarterly filings, holdings, biggest buys and sells, and a clone-performance record computed from its disclosed positions — labeled as a 13F clone record, not as the fund’s actual returns, because fees, shorts, and intra-quarter trading are all outside the filing. Every stock page shows which tracked funds hold it, and the Q3 2026 tracker follows the current season fund by fund. Coverage runs 40 quarters, from 2016Q3 through 2026Q2, so a claim about a fund’s history can be checked against its own filings rather than taken on trust.
Five mistakes to avoid
1. Treating filing-day holdings as current. They are quarter-end holdings, at least 45 days old. 2. Reading value changes as trades. Compare shares. 3. Adding NT filers to HR filers. Resolve notices first, or you double-count. 4. Reading option rows as stock. A put row’s VALUE is underlying value, not premium, and no strike or expiry is disclosed — see our study of superinvestor put options for how little those rows predict. 5. Copying a filing as a portfolio. A 13F is long-only, U.S.-listed, and quarter-end-dated; the fund’s real book includes everything the form omits.
Methodology
Sources. SEC Form 13F rules and the SEC’s Form 13F FAQ (45-day deadline, $100M threshold, weekend roll, long-only scope, NT notices); GetCoattail’s market-wide filing count for 2026Q2 (8,857 filers) and the 147-fund roster criteria above. The November 14, 2026 → November 16, 2026 roll follows from the calendar (November 14, 2026 is a Saturday) and the SEC’s next-business-day rule.
Limits. This is a reading guide, not a filing. For any specific position, the fund’s filing on SEC EDGAR is authoritative, and CUSIP-level matching across quarters can break around corporate actions. For education only — not investment advice.
Revision history
Oct 28, 2026: First published.