SEC ownership filings are usually right, but they are often misread

Stéphane Bancel, CEO of Moderna, sold around $28.7 million of company stock in August 2026, according to the Form 4 he filed with the Securities and Exchange Commission (SEC) on Aug. 7, 2026. The same filing tells the rest of the story. On Aug. 5, he exercised 499,246 stock options at $19.15 a share. He sold the same number of shares in four tranches, at average prices between $56.21 and $58.79. He also exercised his remaining 252,469 options on Aug. 6, increasing his direct holdings to 6,440,260 from 6,187,791.

He sold $28.7 million of stock and also increased his direct holdings by the end of the week. Both of these facts are true, but only one will make it into the headlines. The filing also shows that the trades were made under a Rule 10b5-1 plan, adopted on May 4, 2026. Both of the option tranches were expiring on Aug. 10, 2026.

Much of the work I do involves looking at ownership filings and converting them into data. There is rarely anything wrong with the filings themselves; rather it is how you read them.

13Fs are a snapshot

Large investment managers file their Form 13F every quarter. They must do so within 45 days of the end of the quarter; however, if the 45th day falls on a weekend or holiday, it will be moved to the next business day. In the third quarter of 2026, day 45 is Saturday, Nov. 14, so the deadline is Monday, Nov. 16.

I looked at the 50 investment managers we track on our superinvestors page. This is not a random sample, but a list of widely followed managers. I took the first original filing for each manager for the quarter ending June 30, 2026, from the SEC’s Electronic Data Gathering, Analysis, and Retrieval (EDGAR) filing index, ignoring any amendments. Forty-nine of the 50 managers filed. Thirty-four of them filed on the due date, Aug. 14, 2026. Forty-one of the managers filed within the last three days. The median filing came exactly 45 days after the end of the quarter. In the first quarter of 2026, 32 filed on the due date and 41 within the last three days.

Nothing is wrong with this. However, the portfolio is being reported in mid-August, but it is for June 30. The trades could be from early April. If a position was bought on the first day of the quarter, it may not be visible to the public for up to around 135 days. If it makes the headlines as a new buy, they have had four months to change their minds.

What is missing from the snapshot

As per the SEC guidance, short positions are not reported. Written options are also not reported. Held options are reported, but will be labeled as PUT or CALL. Most of the columns will also show information about the underlying stock.

This is where Scion Asset Management, Michael Burry’s firm, can trip people up. Their latest 13F was filed on Nov. 3, 2025. They have eight positions reported with a value of $1.38 billion. The largest line is Palantir Technologies at $912 million. However, this line is a put option on 5 million shares. This means they benefit when the stock price falls. The second position is Nvidia worth $187 million, also a put. Calls on Pfizer and Halliburton come next. By my calculation from the filing, option lines make up 95% of the reported value, and the shares Scion actually held were worth about $68 million.

The value of the options is the value of the underlying shares, not the fund’s net exposure. The premium paid for the options will not be reported. If you are just looking at the name and value columns, you might think they have the largest position with $912 million in Palantir.

Another issue with this is there are no other 13Fs filed since this one. If you look at any pages showing Burry’s 13F portfolio, they are showing Sept. 30, 2025.

Reading the correct columns

Oaktree Capital Management’s 13F for the second quarter of 2026 has 145 lines with a total value of $7.2 billion. The two largest are put options. One is on the SPDR S&P 500 ETF Trust, an exchange-traded fund that tracks the index, with an underlying value of $1.01 billion. The other is a put on the Invesco QQQ Trust, worth $652 million. The S&P 500 fund is listed under the issuer "STATE STREET CORP." This means a tool that looks up holdings by issuer name could show they have a billion-dollar position in a bank. Another 87 lines are shown as principal amounts, so they are convertible bonds. Of the total value, 26% consists of options and 21% consists of bonds, meaning nearly half of the total isn’t long stock. This isn’t an error; it’s just how the form works.

Unit values

Since Jan. 3, 2023, the SEC has required 13Fs to be in dollar amounts. Baupost Group’s 13F for the second quarter of 2026 shows a total of 5,415,853. Their Amazon line shows 3,743,854 shares with a value of 892,310. That works out to around 24 cents per share. Pershing Square Inc.’s filing for the same quarter shows Amazon with a value of $238.34 a share, exactly 1,000 times more, and the same ratio holds for Restaurant Brands. We therefore read Baupost's portfolio as about $5.4 billion. This is our correction of the unit they filed. They actually stated 5,415,853, so taken literally the portfolio is worth $5.4 million.

Both Berkshire Hathaway and Baupost’s filings for the second quarter show ALPHABET INC. Berkshire’s line shows Class A stock with Committee on Uniform Securities Identification Procedures (CUSIP) number 02079K305. Baupost’s line shows Class C stock with CUSIP 02079K107. Each security has a unique nine-character CUSIP. The issuer name will not distinguish between the classes, but the CUSIP will.

I have fallen into most of these traps. We were tidying up the 13F data for Talval, the research site I run, this October. We found bonds were being counted as shares from the company they were issued by. Alphabet Class C stocks were being shown as Class A. Baupost and another manager appeared to have had their values stored 1,000 times too small. None of this triggered any error messages. It looked like normal data.

Of the 49 managers that filed for the second quarter of 2026, eight had put/call lines, four had bonds, two were still reporting in thousands of dollars and four filed combination reports, where another manager reports part of the holdings. This was calculated by looking at each manager’s holdings table on EDGAR. Pershing Square Capital Management (Bill Ackman’s adviser) only filed a notice. Their $19.5 billion portfolio is shown in the separate 13F from Pershing Square Inc.

Form 4 codes and the plan box

Every line on a Form 4, the report insiders file when they trade their company’s stock, will have a code. P and S mean they bought/sold on the open market or privately. M means they exercised options. F means they had shares withheld or delivered to cover the exercise price or tax. A means they received an award and G means a gift. Only P and S mean they bought/sold in the traditional sense. F does not mean they decided to sell.

Starting April 1, 2023, the SEC has required filers to state whether they traded under a Rule 10b5-1 plan. This is a trading plan set up in advance. Older filings will have nothing stated. If an older filing has no box, it does not mean they made a new decision to sell.

The plan box helps differentiate between sales that look the same in the headlines. I picked four large companies with differing patterns as examples, not as a sample. I added up all the lines with code S from their original Form 4 filings between May 7 and Nov. 3, 2026. Amazon insiders sold $385 million, all of it under plans. Adobe insiders sold about $31.5 million of stock; none of it was under plans.

Who sold

Nvidia insiders sold $1.38 billion, only 1.5% of it under plans. One director accounted for $1.35 billion, in five filings with no plan box ticked. Walmart insiders sold $1.07 billion, 1.7% of it under plans. The Walton Family Holdings Trust, which owns more than 10% of the company, accounted for $1.05 billion. Officers and directors sold around $20 million; most of it was under plans.

None of these numbers tell you what people think of the stock. Directors and families may sell for tax, diversification and estate reasons. The filings show who reported the sales and whether they were reported under a Rule 10b5-1 plan, but they don't necessarily establish the person's reasons for selling.

Schedule 13D doesn’t always mean activism

An investor who becomes the beneficial owner of more than 5% of a company's covered equity securities generally must file Schedule 13D unless eligible to report on Schedule 13G. Under Rule 13d-1, Schedule 13G is mainly for passive holders. In practice, Schedule 13D filers include activists, founding families and control groups.

The Walton family entities filed an amendment to their 13D on Mar. 3, 2026. They show beneficial ownership of 44.21% of Walmart. In Item 4, they state they are amending to show disposals. This includes distributions to beneficiaries of the trust and sales "to meet investment, personal and charitable objectives." They are by far the largest shareholder, and their 13D shows they are selling down. Until Nov. 3, 2026, we marked all 13Ds as activist on our site. We have now corrected this.

What isn’t shown

These numbers are for the 50 managers we track and four companies over six months. The filings can be amended after the dates I have used. I have not tested whether copying 13F portfolios is profitable.

The filings are free and usually accurate. I always check the date of the holdings, the PUT/CALL column, CUSIP and if it is a Form 4, the code and plan box. This takes a few minutes.

Disclosure: I have no positions in any of the securities mentioned. Our site shows Form 13F and Form 4 data.

Legal Disclaimer: This article is provided for general informational and educational purposes only and does not constitute legal advice or create an attorney-client relationship. Laws and regulations vary by jurisdiction and may change over time. Readers should not rely on the information in this article as a substitute for advice from a qualified attorney regarding their individual circumstances. The views expressed are those of the author and do not necessarily reflect the views of Featured News or its affiliates.

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