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ZBIO SCHEDULE 13D/A: SEC filing

An amendment to a Schedule 13D was

Filed with the SEC on · accession 0001953107-26-000015

ZBIO filed a SCHEDULE 13D/A (schedule 13d/a) with the SEC on Aug 19, 2026. An amendment to a Schedule 13D was filed regarding Zenas BioPharma, Inc. (ZBIO). The stock moved -2.1% by the first close after the filing.

Summary of the filing

An amendment to a Schedule 13D was filed regarding Zenas BioPharma, Inc. (ZBIO). The filing indicates a change in a previously reported beneficial ownership position, though specific details are not available in the provided text.

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Key details

Subject companyZenas BioPharma, Inc.

How ZBIO stock reacted

Close before

$31.91

Aug 18, 2026

First close after

-2.07%

$31.25

5 trading days

+5.83%

$33.77

Since filing

-11.44%

$28.26

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Frequently asked questions

What did ZBIO file with the SEC on Aug 19, 2026?

ZBIO filed a SCHEDULE 13D/A (SEC filing). An amendment to a Schedule 13D was filed regarding Zenas BioPharma, Inc. (ZBIO). The filing indicates a change in a previously reported beneficial ownership position, though specific details are not available in the provided text.

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 ZBIO stock react to this filing?

ZBIO closed at $31.91 before the filing and $31.25 on Aug 19, 2026 (-2.07%). Five trading days later: $33.77 (+5.83%).

Other ZBIO SEC filings

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