Rallybio director granted 18,055 stock options

Rallybio Corp director Martin Mackay received a stock option grant tied to his board compensation.

Accepted by SEC EDGAR 02/20/2026 - 06:08 PM EST Learn about SEC filing dates

Rhea-AI Filing Summary

Rallybio Corp director Martin Mackay received a stock option grant tied to his board compensation. The Form 4 shows an award of options to purchase 18,055 shares of common stock at an exercise price of $3.60 per share.

The option was issued under Rallybio’s 2021 Equity Incentive Plan in lieu of $65,000 in retainer fees. It vests in 11 equal installments, each on the last day of the remaining months of calendar year 2026, meaning the award becomes exercisable gradually over that period rather than all at once.

Insider Trade Summary

Grant/Award: 18,055 shares

Grant/Award 1 txn

Insider MACKAY MARTIN

Role Director

Type	Security	Shares	Price	Value
Grant/Award	Option (Right to Buy)	18,055	$3.60	$65K

Holdings After Transaction: Option (Right to Buy) — 18,055 contracts (Direct)

Footnotes (2)

1. F1. The option vests as to the underlying shares of Common Stock in 11 equal installments, each on the last day of each remaining month of calendar year 2026.
2. F2. This option was issued to the reporting person pursuant to the Company's 2021 Equity Incentive Plan in lieu of retainer fees of $65,000.

FAQ

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

What insider transaction did Rallybio (RLYB) disclose for Martin Mackay?

Rallybio reported a stock option grant to director Martin Mackay. He received options for 18,055 shares at a $3.60 exercise price, issued under the 2021 Equity Incentive Plan as part of his board compensation.

How many Rallybio (RLYB) shares are covered by Martin Mackay’s option grant?

The disclosed option grant covers 18,055 Rallybio common shares. This entire amount represents a new award, with 18,055 options reported as beneficially owned following the transaction, reflecting a single compensation-related grant rather than open-market trading.

What is the exercise price of Martin Mackay’s Rallybio (RLYB) stock options?

The option grant has an exercise price of $3.60 per Rallybio share. This price is the cost per share Mackay would pay to exercise the options once they vest under the company’s 2021 Equity Incentive Plan.

How do Martin Mackay’s Rallybio (RLYB) options vest over time?

The options vest in 11 equal installments during 2026. Each installment vests on the last day of each remaining month of calendar year 2026, creating a monthly vesting schedule rather than a single cliff vest date.

Why did Rallybio (RLYB) issue this option grant to Martin Mackay?

The options were issued in lieu of $65,000 in board retainer fees. Instead of receiving cash, Mackay accepted equity compensation via Rallybio’s 2021 Equity Incentive Plan, aligning part of his compensation with the company’s share performance.

Is Martin Mackay’s Rallybio (RLYB) option grant a market purchase or sale?

The filing describes a grant or award acquisition, not a market trade. The options were awarded as compensation under the equity plan, so there was no open-market buying or selling of Rallybio shares in this transaction.

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

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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^*

MACKAY MARTIN

(Last) (First) (Middle)

C/O RALLYBIO CORPORATION

234 CHURCH STREET

(Street)

NEW HAVEN CT 06510

(City) (State) (Zip)

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
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
02/18/2026

4. 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 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

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)	$4.45	02/18/2026		A		18,055		(1)	02/18/2036	Common Stock	18,055(2)	$3.6	18,055	D

Explanation of Responses:

1. The option vests as to the underlying shares of Common Stock in 11 equal installments, each on the last day of each remaining month of calendar year 2026.

2. This option was issued to the reporting person pursuant to the Company's 2021 Equity Incentive Plan in lieu of retainer fees of $65,000.

Remarks:

	By:/s/ Stephen Uden, Attorney-in-Fact	02/20/2026
	** 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.