# How to read a 13F filing: a line-by-line walk through Berkshire Hathaway's latest one URL: https://start.joinautopilot.com/journal/how-to-read-a-13f Updated: 2026-10-13 I'm Chris, one of the co-founders of Autopilot. Open it in the Autopilot app. https://link.joinautopilot.com/eXKr?c=how-to-read-a-13f&af_sub1=intro Open it in the Autopilot app. https://link.joinautopilot.com/eXKr?c=how-to-read-a-13f&af_sub1=body To read a 13F, find the manager on EDGAR, open its latest 13F-HR, and go in order: the cover page, the summary page, then the information table, one line at a time. Add up every line for the same stock as you go. For those unaware, a 13F is the quarterly report big investment managers file with the SEC. It lists their US stock holdings on the last day of the quarter, and anyone can read it for free. Let me explain, using a real one: Berkshire Hathaway's 13F for June 30, 2026. 1) Who files one, and when Any institutional investment manager with investment discretion over $100 million or more in Section 13(f) securities has to file one. That's banks, insurance companies, broker-dealers, pension funds, and advisers, not just hedge funds. A person investing only their own money doesn't file. It's due within 45 days after each quarter ends. If day 45 lands on a weekend or holiday, it moves to the next business day, and the SEC doesn't grant extensions. The next deadline is Monday, November 16, 2026, for the quarter that ended September 30. 2) Find it on EDGAR Here's how to pull up Berkshire's: - Open Berkshire's filings on EDGAR. Its CIK is 1067983, and the link already filters to 13F. - Click Documents next to the latest 13F-HR: accession 0001193125-26-352200, filed August 14, 2026. - You'll see two documents: the primary document, with the cover page and summary page, and the information table. EDGAR notes the SEC "has not necessarily reviewed the information in this filing." You're reading what the manager reported. 3) The cover page and summary page The cover page tells you: - The quarter: 06-30-2026. - Whether it's an amendment. This one isn't. - Who filed: Berkshire Hathaway Inc, Omaha, Form 13F file number 028-04545. - Signed: August 14, 2026, the deadline day. - The report type: 13F Holdings Report. The summary page has three numbers: 14 other included managers, 89 entries, and a value total of $299,253,556,246. The 14 other managers are numbered. GEICO Corp is number 8, National Indemnity Co is 11, and number 4 is Warren E. Buffett. Those numbers come back in the table. 4) The information table, column by column Here's Berkshire's biggest Apple line in the information table: - Name of issuer: APPLE INC. - Title of class: COM, for common stock. - CUSIP: 037833100, the nine-character ID for the security. A FIGI is optional. - Value: 23,341,172,315. That's the closing value on the last trading day of the quarter, rounded to the nearest dollar. It isn't what Berkshire paid. Before January 3, 2023, filers reported values in thousands, so check the filing date on older ones. - Shares: 80,664,820, marked SH. PRN would mean a principal amount. - Put/call: blank, so these are shares, not options. - Investment discretion: DFND, for shared-defined, the code when a parent company and the companies it controls share the decision. The others are SOLE and OTR, for shared-other. - Other managers: 4,11. From the summary page, that's Warren E. Buffett and National Indemnity Co. - Voting authority: 80,664,820 sole, 0 shared, 0 none. Form 13F tells a manager in a shared-defined setup like this to report voting as sole, so all 89 lines say sole. 5) Why Apple takes up 12 lines Apple shows up on 12 lines, because Form 13F has managers split shared holdings by which other managers share them. Each Apple line lists a different set, like 4,5 or 4,8,11. Add up the 12 Apple lines and you get 227,917,808 shares worth $65,950,296,923. Do that for the whole table, and 89 lines become 29 securities. That's 26 companies, because Alphabet, Lennar, and Liberty Live each have two share classes. Two habits that help: - Match lines by CUSIP, not by name. - Compare share counts between quarters. A value moves with the stock price even when nobody trades. Between March 31 and June 30, 2026, Berkshire's Apple share count didn't change, and its Alphabet share count went up by about 48.1 million across both classes. One more thing. Every one of the 89 lines lists number 4, Warren E. Buffett. A 13F doesn't say who made which call. 6) Report types, amendments, and confidential treatment There are three report types: - Holdings report: all of the manager's positions. Filed as a 13F-HR. - Combination report: some of them, with another manager reporting the rest. Also a 13F-HR. - Notice: none, because another manager reports them all. That's a 13F-NT. For June 30, Pershing Square Capital Management filed a notice pointing to its public parent's report. I covered that in Bill Ackman's latest holdings. Amendments are filed as a 13F-HR/A or a 13F-NT/A. A restatement replaces the whole filing to fix an error. A new-holdings amendment adds positions that weren't in the original. That's where confidential treatment comes in. A manager can ask the SEC to keep a position out of the public filing for three, six, or nine months, or a year, in limited cases like an ongoing program of buying or selling. When that ends, or the SEC says no, the manager has six business days to file an amendment adding it. Berkshire has done exactly this. Its 13F for March 31, 2025, filed May 15, 2025, had the confidential treatment box checked. On August 14, 2025, the day confidential treatment expired, it filed a 13F-HR/A adding 1,512,371 D.R. Horton shares, 1,929,972 Lennar Class A shares, 202 Lennar Class B shares, and 5,756,510 Nucor shares. Together they were worth $1.11 billion as of March 31, 2025. To put that into context, anyone reading the original in May 2025 didn't see Berkshire's D.R. Horton, Nucor, or Lennar Class A shares at all. 7) What a 13F leaves out Here's the problem. 13Fs don't have a purchase date. They only have the ending date. So you can't tell if Berkshire bought its Alphabet in April or on June 29, what it paid, or why. The SEC's FAQ and the form leave out more: - Short positions. They aren't reported, and they aren't subtracted from the longs. - Options a manager writes. - Cash and Treasury bills. Berkshire's June 30, 2026 10-Q shows $324.9 billion in short-term Treasury bills in its insurance and other businesses, more than the whole $299.3 billion in the 13F. - Mutual fund shares, and foreign shares that don't trade on a US exchange. - Positions under 10,000 shares and under $200,000, which a manager can choose to leave off. - Anything under confidential treatment. And it's late by design. Berkshire's June 30 holdings went public on August 14. Since then, Berkshire's Form 3 and Form 4 filings show its Lennar Class A stake going from 13,111,741 shares at June 30 to 28,438,045 after purchases through October 2. Those filings cover one company at a time, and they're faster: - Schedule 13D or 13G. Anyone who owns more than 5% of a company's voting shares files one. A 13D is due within five business days, and a 13G is the short form for passive and institutional holders. Berkshire filed a 13G on Lennar on August 14, 2026, and amended it on October 7. - Form 4. Directors, officers, and anyone who owns more than 10% of a company's registered stock report their trades within two business days. Source: SEC EDGAR, Berkshire Hathaway Form 13F-HR filed 8/14/26; Forms 3 and 4 through 10/5/26; Schedule 13G and 13G/A through 10/7/26. 8) What it can tell you about a strategy Read across a few quarters, a 13F shows you: - Concentration. Berkshire's top 15 holdings are about 97% of the value total. - Turnover. What's new, gone, bigger, or smaller. In the June quarter, Berkshire added Alphabet and sold all of its Constellation Brands. - Options. Berkshire's table has no put or call lines. Citadel's amended June 30 13F is about 80% options by value. The two filings look very different. It can't tell you why a position exists, what's hedged against it, or how it did. 9) If you'd rather not read 89 lines every quarter To put that into context, Berkshire's table is 89 lines. Renaissance Technologies' June 30 13F has 3,140. Citadel's amended one has 16,122. You don't have to read them. You don't have to pick the stocks, either. You pick who does, and it runs in the brokerage account you already have. Autopilot Advisers builds tracker Portfolios from them. The Buffett Tracker, Jim Simons Tracker, Citadel Tracker, Point 72, and Dalio Tracker each take the 15 largest holdings in the firm's latest 13F and rebalance with each new one. The Ackman Tracker is built from Pershing Square's public disclosures, including its shareholder letters. The firms don't run these Portfolios, and the trackers don't hold the filing's exact percentages. Every Portfolio has a live performance chart from the day it was added to Autopilot. Not a backtest. As of October 9, 2026, more than $2 billion is invested through Autopilot, and we have over 250,000 users. It's three steps. You connect the brokerage account you already have. You pick a Portfolio. You allocate the money. You give Autopilot Advisers limited authority to place trades. It can't move or withdraw your money. When the Portfolio changes, we send the orders and your broker fills them. The money stays in your account. I want to be honest with you. A tracker built from 13Fs follows them late, with everything they leave out. Some Portfolios go up for years, some are flat for years, and some lose money. Research the person and the Portfolio before you put money in. The full lineup is in Hedge fund and Wall Street Portfolios, and what Berkshire bought and sold in the June quarter is in Berkshire Hathaway's latest 13F. TLDR: A 13F is a big manager's list of US stock holdings on the last day of a quarter, due within 45 days. Find it on EDGAR, read the cover page, summary page, and information table, and add lines up by CUSIP. Berkshire's June 30, 2026 filing has 89 lines covering 29 securities, with Apple alone on 12. A 13F has no purchase dates, shorts, or cash, and positions can be held back under confidential treatment. Autopilot's 13F trackers do the reading for you and rebalance with each new 13F. Frequently asked questions How do I read a 13F filing? Find the manager on SEC EDGAR, filter to 13F, and open the latest 13F-HR. The cover page gives the quarter, filer, and report type. The summary page gives the line count, value total, and a numbered list of other managers. Then read the information table: issuer, class, CUSIP, value, shares, put/call, investment discretion, other managers, and voting authority. Add up lines with the same CUSIP. Berkshire Hathaway's June 30, 2026 filing has 89 lines covering 29 securities. Why might a hedge fund's 13F not reflect their current real positions? Because it's a snapshot of the quarter's last day, filed up to 45 days later, with no purchase dates. It also leaves out shorts, options the manager writes, cash, foreign shares that don't trade on a US exchange, small positions, and anything under confidential treatment. Berkshire's 13F showed 13.1 million Lennar Class A shares at June 30, 2026, and its Form 4s show 28.4 million after October 2. What does a hedge fund's 13F tell you about its strategy? Read across several quarters, it shows how concentrated the holdings are, what's new, gone, bigger, or smaller, and whether the firm reports options. Berkshire's top 15 holdings are about 97% of its June 30, 2026 filing, with no options. Citadel's amended filing for the same date is about 80% options by value. A 13F can't tell you why a position exists or what's hedged against it. What are 13F filings and why do they matter to retail investors? They're quarterly reports of US stock holdings from institutional managers with investment discretion over $100 million or more in 13(f) securities. The SEC says Congress passed the law behind them in 1975 to make institutional holdings more public. For retail investors, they're a free look at what firms like Berkshire Hathaway held at the end of each quarter. They're also late, and they leave out shorts and cash. What is the difference between 13F, 13D, and 13G? A 13F covers a manager's whole portfolio of 13(f) securities once a quarter, due within 45 days. A Schedule 13D or 13G covers one company, when someone owns more than 5% of its voting shares. A 13D is due within five business days and states the holder's purpose. A 13G is the short form for passive and institutional holders. Berkshire filed a 13G on Lennar on August 14, 2026, and amended it October 7. Is there an app that follows hedge fund stock picks? Yes. On Autopilot, Autopilot Advisers builds tracker Portfolios from public 13F filings, like the Buffett Tracker, Citadel Tracker, Point 72, and Dalio Tracker. Each holds the 15 largest positions in the firm's latest 13F and rebalances with each new one. You follow them in the brokerage account you already have, and the firms don't run them. Every 13F is also free on SEC EDGAR. How often do hedge funds have to disclose their holdings publicly? Once a quarter, on Form 13F, within 45 days after the quarter ends, if they have investment discretion over $100 million or more in 13(f) securities. The next deadline is Monday, November 16, 2026. Separately, anyone over 5% of a company's voting shares files a 13D or 13G, and holders over 10% file a Form 4 within two business days of a trade. What are the risks of following a 13F filing that's already 45 days old? You're following positions as of the quarter's last day, so the manager may have sold them, added to them, or hedged them since. You don't know when they bought or what they paid, and shorts and cash aren't there. Some Portfolios built from filings go up for years, some are flat for years, and some lose money. Open it in the Autopilot app. https://link.joinautopilot.com/eXKr?c=how-to-read-a-13f&af_sub1=end "Autopilot" refers to Autopilot Holdings Corp and Autopilot Advisers, LLC, an SEC-registered investment adviser. Individual stocks shown are illustrative and not a recommendation. Investing carries risk-including possible loss of principal-and past performance is not indicative of future results. Figures current as of 10/13/26. View our Customer Relationship Summary and other important info at joinautopilot.com/disclaimer. Portfolios and pilots mentioned in this article: Buffett Tracker (Autopilot): https://start.joinautopilot.com/strategies/buffett-tracker-28825 Returns as of October 19, 2026. Month +0.90%, 3 months +0.01%, YTD +12.5%, 1 year +9.0%, Since start +74.4%. Jim Simons Tracker (Autopilot): https://start.joinautopilot.com/strategies/jim-simons-tracker-101718 Returns as of October 19, 2026. Month -1.1%, 3 months +6.5%, YTD +4.0%, 1 year +1.9%, Since start +141.7%. Citadel Tracker (Autopilot): https://start.joinautopilot.com/strategies/citadel-tracker-45607 Returns as of October 19, 2026. Month -1.4%, 3 months +3.1%, YTD +14.2%, 1 year +22.7%, Since start +120.6%. Point 72 (Autopilot): https://start.joinautopilot.com/strategies/point-72-101723 Returns as of October 19, 2026. Month -4.1%, 3 months -2.7%, YTD +20.3%, 1 year +28.6%, Since start +135.8%. Dalio Tracker (Autopilot): https://start.joinautopilot.com/strategies/dalio-tracker-42512 Returns as of October 19, 2026. Month -1.7%, 3 months +3.9%, YTD +15.3%, 1 year +13.0%, Since start +71.4%. Ackman Tracker (Autopilot): https://start.joinautopilot.com/strategies/ackman-tracker-26963 Returns as of October 19, 2026. Month +3.5%, 3 months +4.0%, YTD +6.7%, 1 year +9.8%, Since start +48.3%.