Beneficial Ownership Report · SCHEDULE 13G/A
Korro Bio, Inc.
KRRONASDAQEQUITYCurrent
Beneficial Ownership Report
Structured filing — SCHEDULE 13G/A
primary_doc.xml
Amendment · This filing reports the amendment as submitted.
Subject company
- Company
- Korro Bio, Inc.
- Company CIK
- 0001703647
- Street
- 60 FIRST STREET, 2ND FLOOR, SUITE 250
- City
- CAMBRIDGE
- State / country code
- MA
- Postal code
- 02141
Statement details
- Amendment number
- 1
- Security class
- Common Stock
- Event date
- 09/30/2026
- Rule designation
- Rule 13d-1(b)
Reporting person 1
- Name
- BlackRock, Inc.
- Citizenship / organization
- DE
- Reporting person type
- HC
- Group designation
- b
- Aggregate amount owned
- 717,813
- Percent of class
- 4.9
- Sole voting power
- 699,169
- Shared voting power
- 0
- Sole dispositive power
- 717,813
- Shared dispositive power
- 0
Item 1
Issuer
Korro Bio, Inc.
Principal executive office address
60 FIRST STREET, 2ND FLOOR, SUITE 250 CAMBRIDGE MA 02141
Item 2
Citizenship
See Item 4 of Cover Page
Filing person
BlackRock, Inc. In accordance with SEC Release No. 34-39538 (January 12, 1998), this Schedule 13G reflects the securities beneficially owned, or deemed to be beneficially owned, by certain business units (collectively, the "Reporting Business Units") of BlackRock, Inc. and its subsidiaries and affiliates. It does not include securities, if any, beneficially owned by other business units whose beneficial ownership of securities are disaggregated from that of the Reporting Business Units in accordance with such release.
Principal business or residence address
BlackRock, Inc., 50 Hudson Yards New York, NY 10001
Item 3
Not applicable indication
N
Item 4
Percent of class
4.9
Amount beneficially owned
717813
Sole voting power
699169
Shared voting power
0
Sole dispositive power
717813
Shared dispositive power
0
Item 5
Not applicable indication
N
Ownership of 5% or less
Y
Item 6
Not applicable indication
N
Ownership on behalf of another person
Various persons have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of the common stock of Korro Bio, Inc.. No one person's interest in the common stock of Korro Bio, Inc. is more than five percent of the total outstanding common shares.
Item 7
Not applicable indication
N
Subsidiaries
See Exhibit 99
Item 8
Not applicable indication
Y
Item 9
Not applicable indication
Y
Item 10
Not applicable indication
N
Certifications
By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11.
Exhibits
Exhibit 24: Power of Attorney Exhibit 99: Item 7
Signature 1
- Reporting person
- BlackRock, Inc.
- Signed
- Spencer Fleming
- Title
- Managing Director
- Date
- 10/27/2026
Filed exhibits
- EXHIBIT 24: POWER OF ATTORNEY ↗PowerOfAttorney.txt
- EXHIBIT 99: ITEM 7 ↗Item_7.txt
Company context
Korro is a clinical-stage biopharmaceutical company leveraging a novel oligonucleotide promoted editing of RNA (OPERA®) platform to develop a new class of genetic medicines for rare and highly prevalent diseases. OPERA provides precise, tissue-directed delivery of RNA-editing oligonucleotides (REOs) that modify the targeted native mRNA transcript to repair or form a de-novo protein with enhanced functionality. The platform combines a suite of capabilities consisting of sophisticated knowledge of transcription biology through ADAR proteins (Adenosine Deaminases Acting on RNA), machine learning optimization of REOs, linker chemistry expertise, along with use of a highly targeted tissue-specific delivery methodology. As such, the OPERA platform has enabled Korro to generate and advance a portfolio of differentiated programs that are designed to harness the body’s natural RNA editing process, providing precise yet transient single base edits to produce therapeutic proteins with augmented activity versus its endogenous counterpart. By editing RNA instead of DNA, Korro is expanding the reach of genetic medicines by delivering additional precision and tunability, which has the potential for increased specificity and improved long-term tolerability. Using an REO-based approach, Korro expects to bring its medicines to patients by leveraging its proprietary OPERA platform with precedented delivery modalities, including N-acetylgalactosamine (GalNAc) conjugated for delivery for subcutan