Korro Bio (KRRO) major holder adds stock and pre-funded warrants in March 2026 buy

Rhea-AI Filing Summary

Korro Bio, Inc. reported that an entity associated with major holder Edward T. Mathers bought additional securities. On March 10, 2026, New Enterprise Associates 17, L.P., for which Mathers is an affiliated manager, acquired 242,945 Pre-Funded Warrants at $11.109 per underlying share and 207,100 shares of Common Stock at $11.110 per share in a purchase coded as an open-market transaction and documented in a Subscription Agreement dated March 9, 2026.

The Pre-Funded Warrants are immediately exercisable at an exercise price of $0.001 per share but contain a Beneficial Ownership Limitation that generally caps the holder’s ownership at 9.99% of Korro Bio’s outstanding Common Stock after exercise, with the cap adjustable on 61 days’ notice up to 19.99%. Following these transactions, indirect holdings reported for Common Stock totaled 1,297,893 shares.

Insider Trade Summary

Net Buyer: 450,045 shares ($4,999,757)

Net Buy 2 txns

Insider Mathers Edward T

Role 10% Owner

Bought 450,045 shs ($5.00M)

Type	Security	Shares	Price	Value
Purchase	Pre-Funded Warrants	242,945	$11.109	$2.70M
Purchase	Common Stock	207,100	$11.11	$2.30M

Holdings After Transaction: Pre-Funded Warrants — 242,945 shares (Indirect, See Note 2); Common Stock — 1,297,893 shares (Indirect, See Note 2)

Footnotes (1)

1. Acquired from the Issuer on March 10, 2026 pursuant to a Subscription Agreement dated March 9, 2026. The Reporting Person is a manager of NEA 17 GP, LLC, which is the sole general partner of NEA Partners 17, L.P. ("NEA Partners 17"). NEA Partners 17 is the sole general partner of New Enterprise Associates 17, L.P. ("NEA 17"), the direct beneficial owner of the securities. The Reporting Person disclaims beneficial ownership within the meaning of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise of such portion of the securities held by NEA 17 in which the Reporting Person has no pecuniary interest. The Pre-Funded Warrants are exercisable at any time after their issuance; provided, however, that the Pre-Funded Warrants may not be exercised to the extent such exercise would cause the number of shares of the Issuer's Common Stock owned by the holder (together with its affiliates and certain other related parties) to exceed 9.99% of the total number of shares of the Issuer's Common Stock immediately after giving effect to such exercise, which percentage may be increased or decreased at the option of the holder upon 61 days' prior notice to the Issuer, not to exceed 19.99%.

Form 4 Insider Transactions: What Each Field Means →

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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X

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^*

Mathers Edward T

(Last) (First) (Middle)

104 5TH AVE

19TH FLOOR

(Street)

NEW YORK NY 10011

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

3. Date of Earliest Transaction (Month/Day/Year)
03/10/2026

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
Common Stock	03/10/2026		P(1)		207,100	A	$11.11	1,297,893	I	See Note 2(2)

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
Pre-Funded Warrants	$0.001	03/10/2026		P(1)		242,945		(3)	(3)	Common Stock	242,945	$11.109	242,945	I	See Note 2(2)

Explanation of Responses:

1. Acquired from the Issuer on March 10, 2026 pursuant to a Subscription Agreement dated March 9, 2026.

2. The Reporting Person is a manager of NEA 17 GP, LLC, which is the sole general partner of NEA Partners 17, L.P. ("NEA Partners 17"). NEA Partners 17 is the sole general partner of New Enterprise Associates 17, L.P. ("NEA 17"), the direct beneficial owner of the securities. The Reporting Person disclaims beneficial ownership within the meaning of Section 16 of the Securities Exchange Act of 1934, as amended, or otherwise of such portion of the securities held by NEA 17 in which the Reporting Person has no pecuniary interest.

3. The Pre-Funded Warrants are exercisable at any time after their issuance; provided, however, that the Pre-Funded Warrants may not be exercised to the extent such exercise would cause the number of shares of the Issuer's Common Stock owned by the holder (together with its affiliates and certain other related parties) to exceed 9.99% of the total number of shares of the Issuer's Common Stock immediately after giving effect to such exercise, which percentage may be increased or decreased at the option of the holder upon 61 days' prior notice to the Issuer, not to exceed 19.99%.

	/s/ Zachary Bambach, attorney-in-fact	03/12/2026
	** Signature of Reporting Person	Date
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