Korro Bio (KRRO) awards 20,132 RSUs to its chief operating officer

Rhea-AI Filing Summary

Korro Bio, Inc. (KRRO) granted its chief operating officer 20,132 restricted stock units linked to its common stock. These RSUs were acquired at a reported price of $0.00 and leave the officer beneficially owning 20,132 shares directly after the transaction. The award was made under the company’s 2023 Stock Option and Incentive Plan and will vest in two equal installments: 50% on June 15, 2026 and 50% on December 15, 2026, provided the officer maintains a continuous Service Relationship through each vesting date.

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
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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^*

Chappell Todd

(Last) (First) (Middle)

C/O KORRO BIO, INC.

60 FIRST STREET, 2ND FLOOR, SUITE 250

(Street)

CAMBRIDGE MA 02141

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Korro Bio, Inc. [ KRRO ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

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

3. Date of Earliest Transaction (Month/Day/Year)
12/15/2025

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
Common Stock(1)	12/15/2025		A		20,132	A	$0.00	20,132	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

Explanation of Responses:

1. Represents shares of common stock issuable upon settlement of a restricted stock unit (RSU) granted under the Issuer's 2023 Stock Option and Incentive Plan (the 2023 Plan) that will vest as follows: 50% on June 15, 2026 and 50% on December 15, 2026, in each case subject to the reporting person maintaining a continuous Service Relationship (as defined in the 2023 Plan) through each such date.

	/s/ Jeffrey Cerio, Attorney-in-fact	12/16/2025
	** 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.

FAQ

What insider equity award did Korro Bio (KRRO) grant to its COO?

Korro Bio’s chief operating officer received 20,132 restricted stock units (RSUs) representing shares of common stock issuable upon settlement under the company’s 2023 Stock Option and Incentive Plan.

When do the RSUs granted to Korro Bio's COO vest?

The RSUs vest in two equal installments: 50% on June 15, 2026 and 50% on December 15, 2026, in each case subject to the officer maintaining a continuous Service Relationship.

How many Korro Bio shares does the COO beneficially own after this transaction?

Following the reported transaction, the chief operating officer beneficially owns 20,132 shares of common stock directly.

Under what plan were the RSUs to Korro Bio's COO granted?

The RSUs were granted under Korro Bio’s 2023 Stock Option and Incentive Plan.

What is the relationship of the reporting person to Korro Bio (KRRO)?

The reporting person is an officer of Korro Bio, serving as its Chief Operating Officer. The boxes for Director and 10% Owner are not checked.

What condition must be met for the COO's RSUs at Korro Bio to vest?

The RSUs will vest only if the reporting person maintains a continuous Service Relationship, as defined in the 2023 Plan, through each vesting date.