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SEPN SCHEDULE 13D/A: SEC filing

An amendment to a Schedule 13D was

Filed with the SEC on · accession 0001346824-26-000228

SEPN filed a SCHEDULE 13D/A (schedule 13d/a) with the SEC on Aug 14, 2026. An amendment to a Schedule 13D was filed regarding Septerna, Inc. (SEPN), indicating a change in a previously reported beneficial ownership position by a major holder. The stock moved -1.4% by the first close after the filing.

Summary of the filing

An amendment to a Schedule 13D was filed regarding Septerna, Inc. (SEPN), indicating a change in a previously reported beneficial ownership position by a major holder. The filing text provided contains only the EDGAR directory listing and no substantive details of the amendment.

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Key details

Subject companySepterna, Inc.

How SEPN stock reacted

Close before

$45.14

Aug 13, 2026

First close after

-1.42%

$44.50

5 trading days

-9.64%

$40.79

Since filing

+8.22%

$48.85

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Frequently asked questions

What did SEPN file with the SEC on Aug 14, 2026?

SEPN filed a SCHEDULE 13D/A (SEC filing). An amendment to a Schedule 13D was filed regarding Septerna, Inc. (SEPN), indicating a change in a previously reported beneficial ownership position by a major holder. The filing text provided contains only the EDGAR directory listing and no substantive details of the amendment.

How do I read a SCHEDULE 13D/A?

A report the company filed with the SEC (the US market regulator). Start with the summary, then the key amounts and names. Compare it with the company’s earlier filings.

Why are SEC filings important?

Public companies must tell the SEC about anything that can change their value — results, leadership changes, big deals, new shares, bankruptcy. Filings are the official source, often before the news. A SCHEDULE 13D/A (schedule 13d/a): A report the company filed with the SEC (the US market regulator).

How did SEPN stock react to this filing?

SEPN closed at $45.14 before the filing and $44.50 on Aug 14, 2026 (-1.42%). Five trading days later: $40.79 (-9.64%).

Other SEPN SEC filings

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