KRRO holder plans Rule 144 sale of common stock

KRRO common shareholders have filed a notice to sell shares under Rule 144.

Rhea-AI Filing Summary

KRRO common shareholders have filed a notice to sell shares under Rule 144. The filing covers 368 shares of common stock, with an aggregate market value of $4,964.32, and notes 14,725,646 shares outstanding as of 08/11/2026 on Nasdaq. The notice also lists recent market sales by affiliated funds between May and July 2026 as background disclosure.

Key Figures

Shares to be sold: 368 shares Aggregate market value of sale: $4,964.32 Shares outstanding: 14,725,646 shares +4 more

7 metrics

Shares to be sold 368 shares Common stock covered by the current Rule 144 notice

Aggregate market value of sale $4,964.32 Estimated value of 368 shares in the planned Rule 144 sale

Shares outstanding 14,725,646 shares KRRO common shares outstanding as of 08/11/2026

Single disclosed sale 06/23/2026 (Fund XI) 101,579 shares for $1,447,785.17 Atlas Venture Fund XI, L.P. sale on 06/23/2026

Single disclosed sale 07/02/2026 (Fund XI) 85,955 shares for $1,206,249.49 Atlas Venture Fund XI, L.P. sale on 07/02/2026

Single disclosed sale 06/23/2026 (Opportunity Fund II) 17,426 shares for $248,369.29 Atlas Venture Opportunity Fund II, L.P. sale on 06/23/2026

Acquisition date of securities 04/22/2024 Private placement from issuer for cash

Key Terms

Rule 144, Private Placement, aggregate market value, securities to be sold

4 terms

Rule 144 regulatory

"shareholders have filed a notice to sell shares under Rule 144"

Rule 144 is a U.S. securities regulation that sets conditions under which restricted or insider-held shares can be legally resold to the public, such as required holding periods, availability of public information, limits on how much can be sold at once, and certain filing requirements. For investors it matters because it determines when previously locked-up shares can enter the market — like a release valve that can increase supply, affect share price, and signal insider intent.

Private Placement financial

"Common Stock | 04/22/2024 | Private Placement | Issuer"

A private placement is a sale of securities directly to a selected group of investors, typically institutions or accredited investors, instead of through a public offering. It lets a company raise money faster and with fewer regulatory steps; for existing shareholders it matters because the newly issued shares, often sold at a discount, increase the share count and can dilute their ownership.

aggregate market value financial

"with an aggregate market value of $4,964.32"

Aggregate market value is the combined price you would pay to buy all outstanding shares of a company or all companies in a group at current market prices — essentially the sum of each stock’s market capitalization. It matters to investors because it shows the overall size and weight of an investment or sector (like the total cost to buy every piece of a puzzle), helps compare scale across companies or markets, and influences index composition and risk exposure.

securities to be sold regulatory

"144: Securities To Be Sold Common Stock"

FAQ

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

What does the KRRO Form 144 filing disclose about planned stock sales?

The Form 144 notice discloses a planned sale of 368 shares of KRRO common stock with an aggregate market value of $4,964.32, referencing 14,725,646 shares outstanding as of August 11, 2026 on Nasdaq.

How many KRRO shares are covered by the new Rule 144 sale notice?

The notice covers 368 shares of KRRO common stock. This is the amount of securities indicated in the planned Rule 144 sale section, separate from the larger historical sales reported for the prior three months.

What is the aggregate market value of KRRO shares in the current Form 144?

The aggregate market value of the 368 KRRO shares covered by the notice is $4,964.32. This figure reflects the estimated market value used for the Rule 144 disclosure at the time of filing.

How many KRRO shares were outstanding when the Form 144 was prepared?

The filing reports 14,725,646 KRRO common shares outstanding as of 08/11/2026. This outstanding share count provides context for the relative size of the 368-share planned sale under Rule 144.

What recent KRRO stock sales by Atlas Venture funds are disclosed?

The filing lists past sales, including 101,579 KRRO shares for $1,447,785.17 on 06/23/2026 and other trades in May–July 2026 by Atlas Venture Fund XI and Atlas Venture Opportunity Fund II as historical disclosure.

How were the KRRO shares originally acquired for the current Form 144 sale?

The securities were acquired in a private placement from the issuer on 04/22/2024 for cash. This acquisition information is included in the Form 144 section describing securities to be sold.

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

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Accepted by SEC EDGAR 08/11/2026 - 06:00 PM EDT Learn about SEC filing dates

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK	0001885327
Filer CCC	XXXXXXXX
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer	Korro Bio, Inc.
SEC File Number	001-39062
Address of Issuer	60 First Street 2nd Floor, Suite 250 Cambridge MASSACHUSETTS 02141
Phone	6174681999
Name of Person for Whose Account the Securities are To Be Sold	Atlas Venture Opportunity Fund II, L.P.
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	Shareholder

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common Stock	Merrill Lynch 555 California Street 18th Floor San Francisco CA 94104	368	4964.32	14725646	08/11/2026	Nasdaq

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common Stock	04/22/2024	Private Placement	Issuer			368	04/22/2024	Cash

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
Atlas Venture Fund XI, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common Stock	05/28/2026	2441	34051.95
Atlas Venture Fund XI, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common Stock	06/22/2026	3382	47178.9
Atlas Venture Fund XI, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common Stock	06/23/2026	101579	1447785.17
Atlas Venture Fund XI, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common Stock	06/24/2026	41345	603694.88
Atlas Venture Fund XI, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common Stock	07/02/2026	85955	1206249.49
Atlas Venture Fund XI, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common Stock	07/06/2026	817	11405.24
Atlas Venture Opportunity Fund II, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common Stock	05/28/2026	419	5845.05
Atlas Venture Opportunity Fund II, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common Stock	06/22/2026	580	8091
Atlas Venture Opportunity Fund II, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common Stock	06/23/2026	17426	248369.29
Atlas Venture Opportunity Fund II, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common Stock	06/24/2026	7093	103567.73
Atlas Venture Opportunity Fund II, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common Stock	07/02/2026	14745	206923.96
Atlas Venture Opportunity Fund II, L.P. 300 Technology Sq Ste 8 Cambridge MA 02139	Common Stock	07/06/2026	8506	118742.91

144: Remarks and Signature

Remarks
Date of Notice	08/11/2026
Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1	04/08/2026
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	Ommer Chohan
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)