RA Capital buys 51,258 Hemab Therapeutics shares

Hemab Therapeutics Holdings, Inc. reported multiple open-market purchases of its Common Stock by entities associated with RA Capital.

Rhea-AI Filing Summary

Hemab Therapeutics Holdings, Inc. reported multiple open-market purchases of its Common Stock by entities associated with RA Capital. Over May 7–11, RA Capital–managed funds bought a total of 51,258 shares at weighted average prices generally between about $23.78 and $25.00 per share, across several transaction ranges noted in the footnotes. Following these purchases, RA Capital–related entities reported indirect ownership of 6,365,783 shares of Hemab common stock. Shares are held directly by RA Capital Healthcare Fund LP, RA Capital Nexus II Fund LP, and RA Capital Nexus IV Fund LP, while RA Capital Management, L.P., its general partner, and principals Peter Kolchinsky and Rajeev Shah act as investment managers and disclaim beneficial ownership except to the extent of their pecuniary interests.

Insider Trade Summary

Net Buyer: 51,258 shares

Net Buy 7 txns

Insider RA CAPITAL MANAGEMENT, L.P., RA Capital Healthcare Fund LP, Kolchinsky Peter, Shah Rajeev M.

Role 10% Owner | 10% Owner | 10% Owner | 10% Owner

Bought 51,258 shs ($1.27M)

Type	Security	Shares	Price	Value
Purchase	Common Stock	14,149	$24.47	$346K
Purchase	Common Stock	25,720	$25.00	$643K
Purchase	Common Stock	1,483	$24.98	$37K
Purchase	Common Stock	7,921	$24.34	$193K
Purchase	Common Stock	1,985	$24.95	$50K
holding	Common Stock	--	--	--
holding	Common Stock	--	--	--

Holdings After Transaction: Common Stock — 7,729,773 shares (Indirect, See footnotes)

Footnotes (9)

1. F1. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $23.775 to $24.685 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.
2. F2. RA Capital Management, L.P. (the "Adviser") is the investment manager for RA Capital Healthcare Fund, L.P. (the "Fund"), RA Capital Nexus II Fund, L.P. (the "Nexus Fund II") and RA Capital Nexus IV Fund, L.P. (the "Nexus Fund IV"). The general partner of the Adviser is RA Capital Management GP, LLC (the "Adviser GP"), of which Dr. Peter Kolchinsky and Mr. Rajeev Shah are the managing members. The Adviser, the Adviser GP, the Fund, Dr. Kolchinsky and Mr. Shah disclaim beneficial ownership of any of the reported securities, except to the extent of their pecuniary interest therein.
3. F3. Held directly by the Fund.
4. F4. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $24.84 to $25.00 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.
5. F5. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $24.80 to $25.00 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.
6. F6. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $23.93 to $24.90 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.
7. F7. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $24.93 to $25.00 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.
8. F8. Held directly by Nexus Fund II.
9. F9. Held directly by Nexus Fund IV.

Key Figures

Shares purchased: 51,258 shares Post-transaction holdings: 6,365,783 shares Purchase price (May 11 block): $25.00 per share +4 more

7 metrics

Shares purchased 51,258 shares Total open-market buys over May 7–11

Post-transaction holdings 6,365,783 shares Indirect Hemab common stock reported after latest purchase

Purchase price (May 11 block) $25.00 per share 25,720-share open-market purchase

Purchase price (May 11 block) $24.47 per share 14,149-share open-market purchase

Purchase price (May 8 block) $24.98 per share 1,483-share open-market purchase

Purchase price (May 7 blocks) $24.34–$24.95 per share 7,921- and 1,985-share open-market purchases

Number of buy transactions 5 transactions Open-market purchases reported in Form 4

Key Terms

weighted average price, open-market purchase, beneficial ownership, pecuniary interest, +1 more

5 terms

weighted average price financial

"The price reported in Column 4 is a weighted average price."

Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.

open-market purchase financial

"transaction_action: "open-market purchase" for Common Stock transactions."

An open-market purchase is when an investor or a company buys shares on a public stock exchange at the going market price, rather than through a private deal. It matters to investors because these purchases change how many shares are available, can push the stock price up or signal confidence from large buyers, and often affect per-share metrics like earnings—think of it like someone buying lots of apples off a grocery shelf, reducing supply and potentially raising the price.

beneficial ownership financial

"disclaim beneficial ownership of any of the reported securities, except to the extent of their pecuniary interest therein."

Beneficial ownership means the person or entity that actually enjoys the benefits of owning shares or other assets — such as receiving dividends, voting rights, or price gains — even if the legal title is held in another name. For investors it matters because knowing who truly controls and profits from a company reveals who can influence decisions, exposes potential conflicts of interest or hidden concentration of power, and affects transparency and risk in the stock.

pecuniary interest financial

"disclaim beneficial ownership ... except to the extent of their pecuniary interest therein."

indirect ownership financial

"ownership_type: "indirect" and direct_or_indirect: "I" for the transactions."

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What insider activity did RA Capital report for Hemab Therapeutics (COAG)?

RA Capital–managed funds reported open-market purchases of Hemab Therapeutics Common Stock, totaling 51,258 shares over May 7–11. These transactions increased their indirect reported holdings to 6,365,783 shares, according to the Form 4 filing.

At what prices did RA Capital buy Hemab Therapeutics (COAG) shares?

RA Capital’s Hemab purchases were executed at weighted average prices within ranges from about $23.78 to $25.00 per share. Footnotes specify separate price ranges for each trade, reflecting multiple executions within those bands.

How many Hemab Therapeutics (COAG) shares does RA Capital now indirectly hold?

After these transactions, entities associated with RA Capital reported indirect ownership of 6,365,783 Hemab common shares. This figure reflects their position following the latest reported open-market purchases in the Form 4 filing.

Which RA Capital entities hold Hemab Therapeutics (COAG) shares reported in this Form 4?

Hemab shares are held directly by RA Capital Healthcare Fund LP, RA Capital Nexus II Fund LP, and RA Capital Nexus IV Fund LP. RA Capital Management, L.P. serves as investment manager for these funds, as described in the footnotes.

Do RA Capital and its principals claim full beneficial ownership of Hemab (COAG) shares?

No. The filing states that RA Capital Management, its general partner, and principals disclaim beneficial ownership of the reported Hemab securities except to the extent of their pecuniary interest in those holdings.

How many open-market purchase transactions did RA Capital report in Hemab (COAG)?

The summary data show five open-market purchase transactions in Hemab common stock, with a net effect of buying 51,258 shares. Two additional entries in the Form 4 reflect holdings rather than new buy or sell transactions.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Accepted by SEC EDGAR 05/11/2026 - 05:44 PM Learn about SEC filing dates

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

RA CAPITAL MANAGEMENT, L.P.

(Last) (First) (Middle)

200 BERKELEY STREET, 18TH FLOOR

(Street)

BOSTON MASSACHUSETTS 02116

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
Hemab Therapeutics Holdings, Inc. [ COAG ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/07/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

	Form filed by One Reporting Person
X	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	05/07/2026		P		7,921	A	$24.34(1)	6,322,446	I	See footnotes(2)(3)
Common Stock	05/07/2026		P		1,985	A	$24.95(4)	6,324,431	I	See footnotes(2)(3)
Common Stock	05/08/2026		P		1,483	A	$24.98(5)	6,325,914	I	See footnotes(2)(3)
Common Stock	05/11/2026		P		14,149	A	$24.47(6)	6,340,063	I	See footnotes(2)(3)
Common Stock	05/11/2026		P		25,720	A	$25(7)	6,365,783	I	See footnotes(2)(3)
Common Stock								1,009,052	I	See footnotes(2)(8)
Common Stock								354,938	I	See footnotes(2)(9)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

1. Name and Address of Reporting Person^*

RA CAPITAL MANAGEMENT, L.P.

(Last) (First) (Middle)

200 BERKELEY STREET, 18TH FLOOR

(Street)

BOSTON MASSACHUSETTS 02116

(City) (State) (Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

RA Capital Healthcare Fund LP

(Last) (First) (Middle)

C/O RA CAPITAL MANAGEMENT, L.P.

200 BERKELEY STREET, 18TH FLOOR

(Street)

BOSTON MASSACHUSETTS 02116

(City) (State) (Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Kolchinsky Peter

(Last) (First) (Middle)

C/O RA CAPITAL MANAGEMENT, L.P.

200 BERKELEY STREET, 18TH FLOOR

(Street)

BOSTON MASSACHUSETTS 02116

(City) (State) (Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Shah Rajeev M.

(Last) (First) (Middle)

C/O RA CAPITAL MANAGEMENT, L.P.

200 BERKELEY STREET, 18TH FLOOR

(Street)

BOSTON MASSACHUSETTS 02116

(City) (State) (Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

Explanation of Responses:

1. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $23.775 to $24.685 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.

2. RA Capital Management, L.P. (the "Adviser") is the investment manager for RA Capital Healthcare Fund, L.P. (the "Fund"), RA Capital Nexus II Fund, L.P. (the "Nexus Fund II") and RA Capital Nexus IV Fund, L.P. (the "Nexus Fund IV"). The general partner of the Adviser is RA Capital Management GP, LLC (the "Adviser GP"), of which Dr. Peter Kolchinsky and Mr. Rajeev Shah are the managing members. The Adviser, the Adviser GP, the Fund, Dr. Kolchinsky and Mr. Shah disclaim beneficial ownership of any of the reported securities, except to the extent of their pecuniary interest therein.

3. Held directly by the Fund.

4. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $24.84 to $25.00 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.

5. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $24.80 to $25.00 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.

6. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $23.93 to $24.90 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.

7. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $24.93 to $25.00 inclusive. The Reporting Persons undertake to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.

8. Held directly by Nexus Fund II.

9. Held directly by Nexus Fund IV.

	/s/ Peter Kolchinsky, Manager of RA Capital Management, L.P.	05/11/2026
	/s/ Peter Kolchinsky, Manager of RA Capital Healthcare Fund GP, LLC the General Partner of RA Capital Healthcare Fund, L.P.	05/11/2026
	/s/ Peter Kolchinsky, individually	05/11/2026
	/s/ Rajeev Shah, individually	05/11/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)