Welcome to our dedicated page for Korro Bio SEC filings (Ticker: KRRO), a comprehensive resource for investors and traders seeking official regulatory documents including 10-K annual reports, 10-Q quarterly earnings, 8-K material events, and insider trading forms.
Korro Bio, Inc. filings document the regulatory record of a biopharmaceutical company developing RNA-editing genetic medicines through its OPERA® platform. Its 8-K reports disclose operating and financial results, corporate presentations, clinical and regulatory program updates, capital-structure activity, and material events tied to its RNA-editing pipeline.
The company’s filings also cover proxy governance, executive compensation, equity incentive and inducement arrangements, employment agreements, and material collaboration and license agreements. Program-related disclosures focus on KRRO-121, hyperammonemia in urea cycle disorders and hepatic encephalopathy, GalNAc-conjugated oligonucleotide research, alpha-1 antitrypsin deficiency, risk factors, and the financing and governance framework supporting Korro Bio’s development-stage operations.
Vincent Loic A reported acquisition or exercise transactions in this Form 4 filing.
Korro Bio, Inc. Chief Scientific Officer Vincent Loic A received an equity award covering 7,500 shares of common stock, issuable upon settlement of restricted stock units (RSUs) granted under the 2023 Stock Option and Incentive Plan. These RSUs vest 50% on July 15, 2027 and 50% on July 15, 2028, subject to maintaining a continuous Service Relationship. Following this grant, he reports direct ownership of 25,797 shares, including 18,358 unvested RSU-based shares scheduled to vest 10,858 on December 15, 2026, 3,750 on July 15, 2027, and 3,750 on July 15, 2028.
Dolan Oliver reported acquisition or exercise transactions in this Form 4 filing.
Oliver Dolan, Senior Vice President, Finance of Korro Bio, Inc., received a grant of 5,500 shares of common stock issuable upon settlement of restricted stock units on July 15, 2026. These RSUs vest 50% on July 15, 2027 and 50% on July 15, 2028, subject to a continuous Service Relationship. Following this award, he directly holds 23,599 shares, including 16,241 unvested RSU shares scheduled to vest between December 15, 2026 and July 15, 2028.
Cerio Jeffrey reported acquisition or exercise transactions in this Form 4 filing.
Korro Bio, Inc. reported that General Counsel Jeffrey Cerio received a grant of 6,500 shares of common stock in the form of restricted stock units (RSUs) under the 2023 Stock Option and Incentive Plan on July 15, 2026, at a stated price of $0.0000 per share. These RSUs will vest 50% on July 15, 2027 and 50% on July 15, 2028, subject to maintaining a continuous Service Relationship. Following this award, Cerio holds 41,793 shares directly, including 27,451 unvested RSUs scheduled to vest in tranches on December 15, 2026 and July 15 of 2027 and 2028.
Chappell Todd reported acquisition or exercise transactions in this Form 4 filing.
Korro Bio, Inc. reported that Chief Operating Officer Todd Chappell received a grant of restricted stock units representing 7,500 shares of common stock under its 2023 Stock Option and Incentive Plan. These RSUs vest 50% on July 15, 2027 and 50% on July 15, 2028, subject to a continuous Service Relationship.
After this award, Chappell beneficially owns 24,464 shares of common stock, including 17,566 shares underlying unvested RSUs scheduled to vest in 2026, 2027 and 2028.
Korro Bio director-linked funds reported open-market sales of 110,023 shares of Common Stock. The transactions were executed on July 2 and July 6, 2026 at weighted average prices around $14 per share, through entities associated with Atlas Venture funds.
The sales were made pursuant to a Rule 10b5-1 trading plan adopted on April 8, 2026, indicating they were pre-scheduled rather than discretionary market-timed trades. Following these transactions, the reporting entities together continue to hold large indirect positions, including 146,305 and 706,556 shares of Korro Bio common stock.
The filing by an issuer shows proposed and recent resale activity in Common Stock related to a Private Placement dated 03/23/2023. The Form 144 lists multiple sales by Atlas Venture affiliates during May–July 2026, including large dispositions on 06/23/2026 and 07/02/2026.
Examples include Atlas Venture Fund XI, L.P.: 101,579 shares sold on 06/23/2026 for $1,447,785.17, and Atlas Venture Opportunity Fund II, L.P.: 17,426 shares sold on 06/23/2026 for $248,369.29.
KRRO files a Form 144 notice reporting recent dispositions of Common Stock by Atlas Venture affiliates. The filing lists multiple sales over late May–early July 2026, including large block sales by Atlas Venture Fund XI, L.P.
Examples shown include sales of 101,579 shares for $1,447,785.17 on 06/23/2026 and 85,955 shares for $1,206,249.49 on 07/02/2026. The notice also shows earlier private placement activity dated 04/22/2024.
Atlas Venture affiliates reported proposed sales of Common Stock of KRRO under Rule 144. The filing lists multiple sale notices in late May and June 2026, including a 101,579-share notice for $1,447,785.17 on 06/23/2026 and other listed transactions on 05/28/2026, 06/22/2026, and 06/24/2026.
Atlas Venture Fund XI, L.P. and Atlas Venture Opportunity Fund II, L.P. filed Form 144 notices reporting proposed sales of Common Stock.
The excerpt lists multiple proposed sale dates and quantities, including a sale of 101,579 shares by Atlas Venture Fund XI on 06/23/2026 (reported value $1,447,785.17) and other smaller tranches on 05/28/2026, 06/22/2026 and 06/24/2026. The filings identify the trades as private-placement-related or resale activity for the issuer on Nasdaq.
Korro Bio director Jean Francois Formela, reporting indirect interests in Atlas Venture funds, disclosed sales of 171,405 shares of common stock from June 22–24, 2026 at weighted-average prices between $13.95 and $15.10 under a Rule 10b5-1 trading plan adopted April 8, 2026.
Following these transactions, Atlas Venture funds associated with him reported holding 169,556 shares of Korro Bio common stock indirectly, with Formela disclaiming Section 16 beneficial ownership except for any pecuniary interest.