Korro Bio COO sells shares for RSU taxes

Korro Bio, Inc. Chief Operating Officer Todd Chappell reported the sale of 3,168 shares of common stock on June 16, 2026 at a weighted-average price of $10.83 per share.

Rhea-AI Filing Summary

Korro Bio, Inc. Chief Operating Officer Todd Chappell reported the sale of 3,168 shares of common stock on June 16, 2026 at a weighted-average price of $10.83 per share. According to the disclosure, this was a mandatory sale solely to satisfy tax withholding obligations arising from the vesting and settlement of restricted stock units granted under the company’s 2023 Stock Option and Incentive Plan. After this tax-related sale, Chappell holds a total of 16,964 shares, which includes 10,066 shares underlying an RSU award scheduled to vest on December 15, 2026, subject to his continued service with the company.

Insider Trade Summary

Net Seller: 3,168 shares

Net Sell 1 txn

Insider Chappell Todd

Role Chief Operating Officer

Sold 3,168 shs ($34K)

Type	Security	Shares	Price	Value
Sale	Common Stock	3,168	$10.83	$34K

Holdings After Transaction: Common Stock — 16,964 shares (Direct)

Footnotes (3)

1. F1. Represents the mandatory sale of shares of common stock solely to satisfy tax withholding obligations incurred upon vesting and settlement of a restricted stock unit (RSU) granted under the Issuer's 2023 Stock Option and Incentive Plan (the 2023 Plan).
2. F2. The price reported in Column 4 is a weighted-average price. The shares were sold in multiple transactions at prices ranging from $10.58 to $11.35, inclusive. Full information regarding the number of shares sold at each separate price can be provided to the issuer, any security holder of the issuer or the staff of the Securities and Exchange Commission upon request.
3. F3. Includes 10,066 shares of common stock issuable upon settlement of a RSU granted under the 2023 Plan that will vest on December 15, 2026 subject to the reporting person maintaining a continuous Service Relationship (as defined in the 2023 Plan) through such date.

Key Figures

Shares sold: 3,168 shares Weighted-average sale price: $10.83 per share Post-transaction holdings: 16,964 shares +2 more

5 metrics

Shares sold 3,168 shares Mandatory sale on June 16, 2026

Weighted-average sale price $10.83 per share Common stock sale on June 16, 2026

Post-transaction holdings 16,964 shares Common stock held after reported transaction

Unvested RSU shares 10,066 shares RSU scheduled to vest on December 15, 2026

Sale price range $10.58–$11.35 per share Multiple trades underlying weighted-average price

Key Terms

restricted stock unit (RSU), 2023 Stock Option and Incentive Plan, weighted-average price, tax withholding obligations

4 terms

restricted stock unit (RSU) financial

"Represents the mandatory sale of shares of common stock solely to satisfy tax withholding obligations incurred upon vesting and settlement of a restricted stock unit (RSU)..."

A restricted stock unit (RSU) is a promise from a company to give an employee company shares (or cash equal to their value) at a future date if certain conditions are met, such as staying with the company or hitting performance targets. For investors, RSUs matter because when they convert into actual shares they increase the number of shares available and can create selling pressure as employees cash out—think of them as a future paycheck paid in company stock.

2023 Stock Option and Incentive Plan financial

"...RSU granted under the Issuer's 2023 Stock Option and Incentive Plan (the 2023 Plan)."

weighted-average price financial

"The price reported in Column 4 is a weighted-average price."

Weighted-average price is the average of multiple prices where each price is counted according to its size or importance—larger trades carry more weight than smaller ones, like averaging course grades by credit hours. It matters to investors because it gives a more realistic picture of the true price paid or received, helping assess trade execution, compare performance, calculate cost basis, and value positions more accurately than a simple average.

tax withholding obligations financial

"...mandatory sale of shares of common stock solely to satisfy tax withholding obligations incurred upon vesting..."

FAQ

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

What insider transaction did Korro Bio (KRRO) report for Todd Chappell?

Korro Bio reported that COO Todd Chappell had 3,168 shares of common stock sold. The transaction occurred on June 16, 2026 and is reported as an open-market sale in the Form 4 filing.

At what price were Todd Chappell’s Korro Bio (KRRO) shares sold?

The reported weighted-average sale price was $10.83 per share. Footnotes note multiple trades executed between $10.58 and $11.35, with full price breakdowns available on request from the company or regulators.

Why were Todd Chappell’s Korro Bio (KRRO) shares sold?

The filing states the shares were sold solely to satisfy tax withholding obligations. These obligations arose when restricted stock units vested and settled under Korro Bio’s 2023 Stock Option and Incentive Plan.

How many Korro Bio (KRRO) shares does Todd Chappell hold after the transaction?

After the tax-related sale, Todd Chappell holds 16,964 shares of common stock. This total includes both currently held shares and shares underlying an unvested RSU award referenced in the Form 4 footnotes.

What future RSU vesting is disclosed for Korro Bio (KRRO) COO Todd Chappell?

The filing states that 10,066 shares of common stock are issuable upon settlement of an RSU. This RSU is scheduled to vest on December 15, 2026, subject to Chappell maintaining a continuous service relationship through that date.

Was Todd Chappell’s Korro Bio (KRRO) share sale discretionary or tax-related?

The Form 4 footnote describes the transaction as a mandatory sale. It explains that the shares were sold solely to cover tax withholding obligations triggered by the vesting of restricted stock units.

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

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Accepted by SEC EDGAR 06/17/2026 - 04:14 PM EDT Learn about SEC filing dates

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^*

Chappell Todd

(Last) (First) (Middle)

C/O KORRO BIO, INC.

60 FIRST STREET, 2ND FLOOR, SUITE 250

(Street)

CAMBRIDGE MASSACHUSETTS 02141

(City) (State) (Zip)

UNITED STATES

(Country)

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
06/16/2026

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)
			Code	V	Amount	(A) or (D)	Price
Common Stock	06/16/2026		S(1)		3,168	D	$10.83(2)	16,964(3)	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 the mandatory sale of shares of common stock solely to satisfy tax withholding obligations incurred upon vesting and settlement of a restricted stock unit (RSU) granted under the Issuer's 2023 Stock Option and Incentive Plan (the 2023 Plan).

2. The price reported in Column 4 is a weighted-average price. The shares were sold in multiple transactions at prices ranging from $10.58 to $11.35, inclusive. Full information regarding the number of shares sold at each separate price can be provided to the issuer, any security holder of the issuer or the staff of the Securities and Exchange Commission upon request.

3. Includes 10,066 shares of common stock issuable upon settlement of a RSU granted under the 2023 Plan that will vest on December 15, 2026 subject to the reporting person maintaining a continuous Service Relationship (as defined in the 2023 Plan) through such date.

	/s/ Jeffrey Cerio, Attorney-in-fact	06/17/2026
	** 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)