Rallybio CFO acquires 2,500 shares, sells 599

The 599-share sale was tied to tax withholding obligations incurred upon partial vesting of a performance stock award.

(Neutral)

(Neutral)How Sentiment works

Sentiment and the balance of points

Rhea-AI Sentiment reads the wording of the document, how positive or negative its language is on a 1 to 5 scale. The balance of points shown with the takes weighs what the document actually discloses, so the two can disagree, for example when a trial that missed its main goal is described in upbeat language.

How Sentiment works How the balance works

Form Type

Rhea-AI Filing Summary

Rallybio Corp (RLYB) Chief Financial Officer Jonathan I. Lieber reported acquiring 2,500 shares of common stock on October 26, 2026, followed by a sale of 599 shares on October 27, 2026, at $16.04 per share. The sale occurred upon partial vesting of a performance stock award solely to satisfy tax withholding obligations incurred upon vesting. No Rule 10b5-1 plan was reported.

Insider Trade Summary

Net Seller: 599 shares

Net Sell 2 txns

Insider Lieber Jonathan I

Role Chief Financial Officer

Sold 599 shs ($10K)

Type	Security	Shares	Price	Value
Sale	Common Stock ^F1	599	$16.04	$10K
Grant/Award	Common Stock	2,500	$0.00	$0.00

Holdings After Transaction: Common Stock — 15,551 shares (Direct)

Footnotes (1)

F1. The reporting person sold shares of common stock upon the partial vesting of a performance stock award, solely to satisfy tax withholding obligations incurred upon vesting.

Key Figures

Shares acquired: 2,500 shares Shares sold: 599 shares Sale price per share: $16.04 per share

3 metrics

Shares acquired 2,500 shares Common stock; October 26, 2026

Shares sold 599 shares Common stock; October 27, 2026

Sale price per share $16.04 per share October 27, 2026

Key Terms

performance stock award, tax withholding obligations, Rule 10b5-1 plan

3 terms

performance stock award financial

"partial vesting of a performance stock award"

tax withholding obligations financial

"solely to satisfy tax withholding obligations"

Rule 10b5-1 plan financial

"No Rule 10b5-1 plan was reported"

A Rule 10b5-1 plan is a prearranged, written schedule that lets corporate insiders buy or sell company stock at set times or amounts, even if they later learn material nonpublic information. Think of it like setting an automatic thermostat for trades: it creates a clear record that trades were planned in advance, reducing the risk of insider-trading accusations and helping investors trust that insider transactions are routine rather than based on secret information.

FAQ

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

How many shares did Rallybio (RLYB) CFO Jonathan I. Lieber sell, and at what price?

Jonathan I. Lieber sold 599 shares of common stock at $16.04 per share on October 27, 2026. The sale occurred upon partial vesting of a performance stock award, solely to satisfy tax withholding obligations incurred upon vesting. No Rule 10b5-1 plan was reported.

How many shares did Rallybio (RLYB) CFO Jonathan I. Lieber acquire?

Jonathan I. Lieber reported acquiring 2,500 shares of common stock in a grant or award acquisition on October 26, 2026.

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

Form 4 Insider Transactions: What Each Field Means →

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google

Add on Google

Available on EDGAR 10/28/2026 - 05:04 PM EDT Accepted by SEC EDGAR 10/28/2026 - 05:03 PM EDT

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)
10/26/2026

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)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	10/26/2026		A		2,500	A	$0	16,150	D
Common Stock	10/27/2026		S		599⁽¹⁾	D	$16.04	15,551	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)
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)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)

Explanation of Responses:

1. The reporting person sold shares of common stock upon the partial vesting of a performance stock award, solely to satisfy tax withholding obligations incurred upon vesting.

	By: /s/ Stephen Uden, Attorney-in-Fact	10/28/2026
	** 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)

Source: View Original Filing on SEC EDGAR