Sec Form 4 Filing - SHANNON TIMOTHY M @ Rallybio Corp - 2021-07-28

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

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, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person SHANNON TIMOTHY M 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) (Last) (First) (Middle) C/O RALLYBIO CORPORATION, 234 CHURCH STREET, SUITE 1020 3. Date of Earliest Transaction (MM/DD/YY) 07/28/2021 (Street) NEW HAVEN, CT06510 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 07/28/2021 J( 1 ) 2,332,789 A 2,332,789 I Canaan XI L.P. ( 2 ) Common Stock 08/02/2021 P 76,923 A $ 13 2,409,712 I Canaan XI L.P. ( 2 )

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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 7. Title and Amount of Underlying Securities (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 of Derivative Security: 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 Series A-1 Preferred Units ( 1 ) 07/28/2021 J( 1 ) 1,795,946 ( 1 ) ( 1 ) Common Stock ( 3 ) 282,044 ( 1 ) 0 I Canaan XI L.P. ( 2 ) Series A-2 Preferred Units ( 1 ) 07/28/2021 J( 1 ) 8,742,654 ( 1 ) ( 1 ) Common Stock ( 3 ) 1,372,990 ( 1 ) 0 I Canaan XI L.P. ( 2 ) Series B Preferred Units ( 1 ) 07/28/2021 J( 1 ) 4,315,676 ( 1 ) ( 1 ) Common Stock ( 3 ) 677,755 ( 1 ) 0 I Canaan XI L.P. ( 2 ) Option (Right to Buy) $ 13 07/28/2021 A 13,440 ( 4 ) ( 4 ) Common Stock 13,440 $ 0 13,440 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other SHANNON TIMOTHY M C/O RALLYBIO CORPORATION 234 CHURCH STREET, SUITE 1020 NEW HAVEN, CT06510 X Signatures By: /s/ Michael Greco, Attorney-in-Fact 08/04/2021 Signature of Reporting Person Date

Explanation of Responses:

( 1 )The Series A-1 Preferred Units, Series A-2 Preferred Units and Series B Preferred Units (collectively, the "Preferred Units") reported herein were preferred units of Rallybio Holdings, LLC. The shares of common stock of the Issuer were received on July 28, 2021 pursuant to the Plan of Liquidation and Dissolution, dated July 28, 2021, among Rallybio Holdings, LLC and its members (the "Plan of Liquidation"). Pursuant to the Plan of Liquidation, the holders of Preferred Units received approximately 6.37 shares of common stock of the Issuer for each Preferred Unit. Rallybio Holdings, LLC was subsequently dissolved. The Preferred Units had no expiration date prior to the liquidation. ( 2 )The reported securities are held directly by Canaan XI L.P. (the "Canaan Fund"). The sole general partner of the Canaan Fund is Canaan Partners XI LLC ("Canaan XI", and together with the Canaan Fund, the "Canaan Entities"), and may be deemed to have sole voting, investment and dispositive power with respect to the shares held by the Canaan Fund. The Reporting Person is a manager and member of Canaan XI. The Reporting Person disclaims Section 16 beneficial ownership in the securities held by the Canaan Entities, except to the extent of his pecuniary interest therein, if any, in such securities by virtue of the limited liability company interest he owns in Canaan XI. ( 3 )Prior to the effectiveness of the Plan of Liquidation, the Preferred Units were convertible into shares of common units of Rallybio Holdings, LLC. ( 4 )The option vests as to the underlying shares of Common Stock on the earlier of July 28, 2022 and the date of the first annual meeting of stockholders of the Issuer following the closing of its initial public offering. The option expires on July 28, 2031.

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