Korro Bio (KRRO) COO awarded 38,000-share stock option grant

Rhea-AI Filing Summary

Korro Bio, Inc. reported that Chief Operating Officer Todd Chappell received a stock option award for 38,000 derivative securities described as a stock option (right to buy) common stock. The option has an exercise price of $13.05 per share and was granted on February 2, 2026.

The grant was made for no purchase price and leaves Chappell with 38,000 stock options beneficially owned directly. These options expire on February 1, 2036 and vest in 48 equal monthly installments starting February 2, 2026, conditioned on his continued service at 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)
02/02/2026

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

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
Stock Option (Right to Buy)	$13.05	02/02/2026		A		38,000		(1)	02/01/2036	Common Stock	38,000	$0	38,000	D

Explanation of Responses:

1. The shares subject to the option vest in 48 equal monthly installments commencing from February 2, 2026, subject to the Reporting Person's continued service on each such vesting date.

	/s/ Jeffrey Cerio, Attorney-in-fact	02/03/2026
	** 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.

FAQ

What insider transaction did Korro Bio (KRRO) report for its COO?

Korro Bio reported a stock option grant to Chief Operating Officer Todd Chappell. He received options covering 38,000 shares of common stock at a $13.05 exercise price, expiring February 1, 2036, as part of his equity compensation.

How many Korro Bio (KRRO) shares are covered by the new stock option grant?

The new stock option grant covers 38,000 shares of Korro Bio common stock. These are derivative securities giving Todd Chappell the right to buy shares at a fixed $13.05 exercise price over the option term.

What is the exercise price of the Korro Bio (KRRO) COO’s stock options?

The exercise price of the stock options granted to Korro Bio’s Chief Operating Officer is $13.05 per share. This means he can buy up to 38,000 common shares at that fixed price if and when options vest.

When do the Korro Bio (KRRO) COO’s new stock options vest?

The options vest in 48 equal monthly installments starting February 2, 2026. Each monthly vesting is conditioned on Todd Chappell’s continued service with Korro Bio on the applicable vesting date, spreading vesting over four years.

When do the newly granted Korro Bio (KRRO) stock options expire?

The stock options granted to Korro Bio’s Chief Operating Officer expire on February 1, 2036. After that date, any unexercised portion of the 38,000-share option grant can no longer be used to purchase common stock.

Does the Korro Bio (KRRO) Form 4 show direct or indirect ownership of the options?

The Form 4 shows that the 38,000 stock options are held as direct ownership. There is no referenced intermediary entity, and the filing lists Todd Chappell as the direct beneficial owner of the derivative securities.