Rallybio CEO exercises options for 33,244 shares

The option was granted under the 2021 Equity Incentive Plan and vests in 48 equal monthly installments until fully vested on February 14, 2029.

Rhea-AI Filing Summary

Rallybio Corp Chief Executive Officer Stephen Uden exercised options on October 27, 2026, to acquire 33,244 common shares at an exercise price of $6.08 per share. His directly held common-stock position after the exercise was 148,864 shares. The reported option balance after the transaction was 0 shares, and the option's expiration date was February 14, 2035.

Insider Trade Summary

33,244 shares exercised/converted

Exercise 2 txns

Insider Uden Stephen

Role Chief Executive Officer

Type	Security	Shares	Price	Value
Exercise	Option (Right to Buy) F1	33,244	$0.00	$0.00
Exercise	Common Stock	33,244	$6.08	$202K

Holdings After Transaction: Option (Right to Buy) — 0 contracts (Direct); Common Stock — 148,864 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

Shares acquired through option exercise: 33,244 shares Exercise price: $6.08 per share Direct common-stock holdings after exercise: 148,864 shares +2 more

5 metrics

Shares acquired through option exercise 33,244 shares October 27, 2026

Exercise price $6.08 per share October 27, 2026 option exercise

Direct common-stock holdings after exercise 148,864 shares Reported after the October 27, 2026 exercise

Option shares following transaction 0 shares Reported after the October 27, 2026 transaction

Option expiration date February 14, 2035 Option exercised on October 27, 2026

Key Terms

Option (Right to Buy), 2021 Equity Incentive Plan, monthly installments

3 terms

Option (Right to Buy) technical

"Option (Right to Buy)"

2021 Equity Incentive Plan technical

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

monthly installments technical

"vests in 48 equal monthly installments"

Monthly installments are regular, fixed payments made each month to gradually pay off a larger amount, such as a loan or purchase. Think of it like paying for a big item in small, manageable parts instead of all at once. For investors, understanding installment payments helps gauge how debts are structured and how they might affect financial stability or cash flow over time.

FAQ

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

How many RLYB shares did CEO Stephen Uden acquire through option exercise?

Stephen Uden exercised options on October 27, 2026, to acquire 33,244 Rallybio common shares at an exercise price of $6.08 per share. His directly held common-stock position after the exercise was 148,864 shares.

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

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Available on EDGAR 10/29/2026 - 05:20 PM EDT Accepted by SEC EDGAR 10/29/2026 - 05:20 PM EDT 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^*

Uden Stephen

(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)

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
10/27/2026

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	10/27/2026		M		33,244	A	$6.08	148,864	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	10/27/2026		M			33,244	(1)	02/14/2035	Common Stock	33,244	$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, Attorney-in-Fact	10/29/2026
	** 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)