Rallybio CFO exercises options for 5,000 shares

Rallybio's chief financial officer had 9,740 directly held common shares following the reported exercise.

Rhea-AI Filing Summary

Rallybio Corp (RLYB) Chief Financial Officer Jonathan I. Lieber exercised options covering 5,000 shares on September 29, 2026, at an exercise price of $6.08 per share, and acquired 5,000 common shares. He reported 9,740 directly held common shares following the transaction. The option was granted under Rallybio's 2021 Equity Incentive Plan and vests in 48 equal monthly installments until fully vested on February 14, 2029.

Insider Trade Summary

5,000 shares exercised/converted

Exercise 2 txns

Insider Lieber Jonathan I

Role Chief Financial Officer

Type	Security	Shares	Price	Value
Exercise	Option (Right to Buy) F1	5,000	$0.00	$0.00
Exercise	Common Stock	5,000	$6.08	$30K

Holdings After Transaction: Option (Right to Buy) — 0 contracts (Direct); Common Stock — 9,740 shares (Direct)

Footnotes (1)

1. F1. The option is granted under the Company's 2021 Equity Incentive Plan. The option vests in 48 equal monthly installments until fully vested on February 14, 2029.

Key Figures

Options exercised: 5,000 shares Common shares acquired: 5,000 shares Exercise price: $6.08 per share +3 more

6 metrics

Options exercised 5,000 shares September 29, 2026

Common shares acquired 5,000 shares September 29, 2026

Exercise price $6.08 per share Option exercise on September 29, 2026

Direct common shares following transaction 9,740 shares Reported following the September 29, 2026 transaction

Vesting installments 48 equal monthly installments Under the 2021 Equity Incentive Plan

Full vesting date February 14, 2029 Option vesting

Key Terms

2021 Equity Incentive Plan, 48 equal monthly installments, fully vested

3 terms

2021 Equity Incentive Plan technical

"granted under the Company's 2021 Equity Incentive Plan"

48 equal monthly installments technical

"vests in 48 equal monthly installments"

fully vested technical

"until fully vested on February 14, 2029"

FAQ

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How many RLYB shares did Jonathan I. Lieber acquire through option exercise?

Jonathan I. Lieber acquired 5,000 Rallybio common shares through exercise of options on September 29, 2026, at an exercise price of $6.08 per share. He reported 9,740 directly held common shares following the transaction.

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

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Available on EDGAR 10/01/2026 - 05:33 PM Accepted by SEC EDGAR 10/01/2026 - 05:32 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^*

Lieber Jonathan I

(Last) (First) (Middle)

C/O RALLYBIO CORPORATION

PO BOX 325

(Street)

EAST BERLIN CONNECTICUT 06023

(City) (State) (Zip)

UNITED STATES

(Country)

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

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

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
09/29/2026

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

X	Form filed by One Reporting Person
	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	09/29/2026		M		5,000	A	$6.08	9,740	D

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
Option (Right to Buy)	$6.08	09/29/2026		M			5,000	(1)	02/14/2035	Common Stock	5,000	$0.00	0	D

Explanation of Responses:

1. The option is granted under the Company's 2021 Equity Incentive Plan. The option vests in 48 equal monthly installments until fully vested on February 14, 2029.

	By: /s/ Jonathan Lieber	10/01/2026
	** 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)