Korro Bio (KRRO) grants 21,482 RSUs to finance executive, vesting in 2026

Rhea-AI Filing Summary

Korro Bio reported an insider equity award to its Senior Vice President, Finance. On December 15, 2025, the officer received 21,482 shares of common stock issuable upon settlement of a restricted stock unit (RSU) grant at a reported price of $0.00 per share under the company’s 2023 Stock Option and Incentive Plan.

The RSUs 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 as defined in the plan through each vesting date. Following this grant, the reporting person beneficially owns 21,482 shares of Korro Bio common stock issuable upon RSU settlement, held directly.

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^*

Dolan Oliver

(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)
	Senior Vice President, Finance

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		21,482	A	$0.00	21,482	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 transaction did Korro Bio (KRRO) disclose in this filing?

Korro Bio disclosed that its Senior Vice President, Finance received a grant of 21,482 restricted stock units (RSUs), reported as common stock issuable upon settlement at a price of $0.00 per share.

When do the 21,482 RSUs granted by Korro Bio (KRRO) vest?

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

What plan governs the RSU grant reported by Korro Bio (KRRO)?

The 21,482 RSUs were granted under Korro Bio’s 2023 Stock Option and Incentive Plan, referred to in the filing as the 2023 Plan.

How many securities does the Korro Bio (KRRO) officer beneficially own after this RSU grant?

After the reported transaction, the officer beneficially owns 21,482 shares of Korro Bio common stock issuable upon settlement of RSUs, held in direct ownership.

Is the Korro Bio (KRRO) RSU grant subject to any service conditions?

Yes. The RSUs will vest only if the reporting person maintains a continuous Service Relationship, as defined in the 2023 Plan, through each vesting date in 2026.

Was the Korro Bio (KRRO) RSU grant reported as a purchase or a grant?

The transaction was coded as an acquisition ("A") of common stock issuable upon RSU settlement at a $0.00 price, indicating an equity grant rather than a market purchase.