Martin Mackay - 18 Feb 2026 Form 4 Insider Report for Rallybio Corp (RLYB)

Reporting relationship: Director
Issuer ticker: RLYB
Reported as of: 18 Feb 2026
Net transaction value: +$64,998
SEC form: 4
Accepted by SEC: 20 Feb 2026, 18:08:28 UTC
Prior SEC filing: 02 Jul 2025
Next SEC filing: 16 Apr 2026
Source filing: View source filing
Reporting owner signature: By:/s/ Stephen Uden, Attorney-in-Fact

Key filing fact

Martin Mackay filed Form 4 for Rallybio Corp (RLYB) on 20 Feb 2026.

Key facts

This page summarizes Martin Mackay's Form 4 filing for Rallybio Corp (RLYB).
1 reported transaction and 1 derivative row are listed below.
Accepted by SEC: 20 Feb 2026, 18:08.

Change

Previous filing in this sequence was filed on 02 Jul 2025.
Current net transaction value: +$64,998.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001414815 Primary reporting owner

MACKAY MARTIN

Relationship: Director
Address: C/O RALLYBIO CORPORATION, 234 CHURCH STREET, NEW HAVEN
Signature: By:/s/ Stephen Uden, Attorney-in-Fact
Signature date: 20 Feb 2026

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

RLYB transaction Derivative

Option (Right to Buy)

Award

Transaction value: $64,998
Shares: +18,055
Change %
Price: $3.60
Shares after: 18,055
Date: 18 Feb 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 18,055
Exercise price: $4.45
Footnotes: F1, F2

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 2 footnotes

Footnote 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.

Footnote 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.