FMR LLC discloses 211,798 Rallybio Corp (RLYB) shares in Form 3

Rhea-AI Filing Summary

FMR LLC filed an initial ownership report for Rallybio Corp, disclosing indirect beneficial ownership of 211,798 shares of Common Stock. These shares are held through F-Prime Capital Partners Life Sciences Fund VI LP. The filing records this position as a holding rather than a new purchase or sale.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider FMR LLC

Role 10% Owner

Type	Security	Shares	Price	Value
holding	Common Stock	--	--	--

Holdings After Transaction: Common Stock — 211,798 shares (Indirect, F-Prime Capital Partners Life Sciences Fund VI LP)

Footnotes (1)

Understanding Insider Trading Forms →

SEC Form 3

FORM 3

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

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

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

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1. Name and Address of Reporting Person^*

FMR LLC

(Last) (First) (Middle)

245 SUMMER STREET

(Street)

BOSTON MA 02210

(City) (State) (Zip)

2. Date of Event Requiring Statement (Month/Day/Year)
03/04/2026

3. Issuer Name and Ticker or Trading Symbol
Rallybio Corp [ RLYB ]

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

	Director	X	10% Owner
	Officer (give title below)	X	Other (specify below)
			See Remark 1

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

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

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

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	211,798	I	F-Prime Capital Partners Life Sciences Fund VI LP

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

Remarks:

Remark 1: Abigail P. Johnson is a Director, the Chairman and the Chief Executive Officer of FMR LLC. Members of the Johnson family, including Abigail P. Johnson, are the predominant owners,directly or through trusts, of Series B voting common shares of FMR LLC, representing 49% of the voting power of FMR LLC. The Johnson family group and all other Series B shareholders haveentered into a shareholders' voting agreement under which all Series B voting common shares will be voted in accordance with the majority vote of Series B voting common shares. Accordingly,through their ownership of voting common shares and the execution of the shareholders' voting agreement, members of the Johnson family may be deemed, under the Investment Company Act of 1940,to form a controlling group with respect to FMR LLC. The address of Abigail P. Johnson is c/o FMR LLC, 245 Summer Street, Boston, MA 02110. Remark 2: The filing of this statement shall not bedeemed to be an admission that, for purposes of Section 16 of the Securities Exchange Act of 1934 or otherwise, the undersigned are the beneficial owners of any securities reported herein. Remark 3: F-Prime Capital Partners Life Sciences Advisors Fund VI LP (FPCPLSA) is the general partner of F-Prime Capital Partners Life Sciences Fund VI LP. FPCPLSA is solely managed by Impresa Management LLC, the managing member of its general partner and its investment manager. Impresa Management LLC is owned, directly or indirectly, by various shareholders and employees of FMR LLC, including certain members of the Johnson family.

	/s/ Stephanie J. Brown, Duly authorized under Powers of Attorney, by and on behalf of FMR LLC and its direct and indirect subsidiaries, and Abigail P. Johnson	03/10/2026
	** 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 5 (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).
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FAQ

What does FMR LLC’s Form 3 filing for RLYB show?

FMR LLC’s Form 3 shows indirect beneficial ownership of 211,798 Rallybio Corp common shares. The position is reported as a holding, indicating existing ownership rather than a newly executed transaction in the reported period.

How many Rallybio Corp (RLYB) shares does FMR LLC report owning?

FMR LLC reports indirect beneficial ownership of 211,798 shares of Rallybio Corp common stock. This figure reflects the total shares held following the reported holding entry in the Form 3 insider ownership statement.

Is FMR LLC a 10% owner of Rallybio Corp (RLYB)?

Yes. The filing indicates FMR LLC is a ten percent owner of Rallybio Corp. This status triggers the requirement to file Form 3, which discloses its indirect beneficial ownership in the company’s common stock.

How are FMR LLC’s Rallybio Corp (RLYB) shares held?

The Form 3 states the 211,798 Rallybio Corp common shares are held indirectly through F-Prime Capital Partners Life Sciences Fund VI LP. The nature of ownership is reported as indirect, rather than directly in FMR LLC’s own name.

Does FMR LLC’s Form 3 for RLYB show any recent insider trades?

No recent trades are indicated; the entry is classified as a holding. The transaction summary shows zero buy or sell transactions and one holding entry, so the filing primarily records existing indirect ownership of Rallybio Corp shares.