John Maraganore - 29 Jan 2026 Form 4 Insider Report for Hemab Therapeutics Holdings, Inc. (COAG)

Reporting relationship: Director
Issuer ticker: COAG
Reported as of: 29 Jan 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 04 May 2026, 16:20:06 UTC
Prior SEC filing: 26 Jun 2025
Next SEC filing: 18 Mar 2026
Source filing: View source filing
Reporting owner signature: /s/ Mads Nikolaj Behrndt-Eriksen, as Attorney-in-Fact

Key filing fact

John Maraganore filed Form 4 for Hemab Therapeutics Holdings, Inc. (COAG) on 04 May 2026.

Key facts

This page summarizes John Maraganore's Form 4 filing for Hemab Therapeutics Holdings, Inc. (COAG).
5 reported transactions and 3 derivative rows are listed below.
Accepted by SEC: 04 May 2026, 16:20.

Change

Previous filing in this sequence was filed on 26 Jun 2025.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001180432 Primary reporting owner

MARAGANORE JOHN

Relationship: Director
Address: C/O HEMAB THERAPEUTICS HOLDINGS, INC., 101 MAIN STREET, SUITE 1220, CAMBRIDGE
Signature: /s/ Mads Nikolaj Behrndt-Eriksen, as Attorney-in-Fact
Signature date: 04 May 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

COAG transaction

Common Stock

Conversion of derivative security

Transaction value
Shares: +17,974
Change %
Price
Shares after: 17,974
Date: 04 May 2026
Ownership: Direct
Footnotes: F1

COAG transaction

Common Stock

Conversion of derivative security

Transaction value
Shares: +17,974
Change %: +100%
Price
Shares after: 35,948
Date: 04 May 2026
Ownership: Direct
Footnotes: F1

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

COAG transaction Derivative

Warrants (Right to Buy)

Award

Transaction value
Shares: +107,338
Change %
Price: $0.000000^*
Shares after: 107,338
Date: 29 Jan 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 107,338
Exercise price: $6.00
Footnotes: F1

COAG transaction Derivative

Series B Preferred Stock

Conversion of derivative security

Transaction value
Shares: -817
Change %: -100%
Price: $0.000000^*
Shares after: 0
Date: 04 May 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 17,974
Exercise price
Footnotes: F1, F2

COAG transaction Derivative

Series C Preferred Stock

Conversion of derivative security

Transaction value
Shares: -817
Change %: -100%
Price: $0.000000^*
Shares after: 0
Date: 04 May 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 17,974
Exercise price
Footnotes: F1, F2

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 2 footnotes

Footnote F1

The warrant was granted on January 29, 2026. The shares underlying the warrant vest over three years in equal monthly installments from January 1, 2026 through January 1, 2029.

Footnote F2

Each share of Series B Preferred Stock and Series C Preferred Stock converted into 22 shares of common stock without payment of further consideration upon closing of the initial public offering of the Issuer's common stock. The shares had no expiration date.