SCHEDULE: Korro Bio: Major Holders Sell Shares Amidst Filing

Sentiment:

Schedule 13D Amendment 4 August 2026 5:13 PM

Korro Bio, Inc. has filed an amendment to its Schedule 13D, detailing significant transactions in its common stock by major holders Atlas XI and AVOF II over the past sixty days.

Summary

This filing is an amendment to a previous Schedule 13D, reporting transactions in Korro Bio, Inc. common stock by Atlas Venture Fund XI, L.P. (Atlas XI) and Atlas Venture Opportunity Fund II, L.P. (AVOF II).
Over the period from May 28, 2026, to July 6, 2026, both Atlas XI and AVOF II engaged in multiple sales of Korro Bio common stock.
Atlas XI sold a total of 300,000 shares across several transactions, with prices ranging from $13.95 to $14.98.
AVOF II sold a total of 51,000 shares across several transactions, with prices ranging from $13.95 to $14.98.
As of the filing date, Atlas XI, along with its general partners, beneficially owns 706,556 shares, representing 4.9% of the outstanding common stock.
As of the filing date, AVOF II, along with its general partners, beneficially owns 146,305 shares, representing 1.0% of the outstanding common stock.
Collectively, the reporting persons beneficially own 852,861 shares, representing an estimated 5.9% of the Issuer's outstanding Common Stock.
The filing notes that the outstanding shares of common stock were 14,422,571 as of May 4, 2026.

Sentiment

Score: 3

Explanation: StockSavvy.ai views this filing as negative due to significant stock sales by major holders, indicating a potential lack of confidence or a need for liquidity, which could pressure the stock price.

Negatives

Significant sales of common stock by major holders Atlas XI and AVOF II occurred between May 28, 2026, and July 6, 2026.
Atlas XI sold a total of 300,000 shares.
AVOF II sold a total of 51,000 shares.
The sales occurred at prices ranging from $13.95 to $14.98 per share.
The reporting persons collectively hold 5.9% of the outstanding common stock after these transactions.

Risks

The substantial sales by major holders could indicate a lack of confidence in future stock performance or a need for liquidity, potentially leading to downward pressure on the stock price.
While the reporting persons disclaim group membership, their common control and coordinated sales activity might be interpreted by the market as a unified selling strategy.

Future Outlook

The filing primarily reports past transactions and does not contain specific forward-looking statements or guidance from Korro Bio, Inc. management regarding future performance.

Management Comments

The reporting persons disclaim group membership, and this Schedule 13D shall not be deemed an admission that the Reporting Persons are members of a group for purposes of Section 13 or for any other purposes.

Industry Context

StockSavvy.ai notes that significant sales by venture capital funds, as seen in this filing, can sometimes precede or coincide with periods of increased volatility or strategic shifts for biotech companies, especially if the sales are substantial relative to the fund's overall stake.

Stakeholder Impact

Shareholders may be concerned by the significant stock sales from major holders, potentially impacting share price and investor sentiment.
Creditors and other debt holders may view the sales as a sign of reduced confidence, although the direct impact is likely minimal unless it signals broader financial distress.

Next Steps

Monitor future filings for any further changes in beneficial ownership by Atlas XI and AVOF II.
Observe Korro Bio, Inc.'s stock performance and any subsequent company announcements for context regarding these sales.

Key Dates

Date	Description
2023-11-13	Original Schedule 13D filing date.
2026-05-04	Date as of which outstanding shares of common stock were reported as 14,422,571.
2026-05-07	Date Korro Bio, Inc.'s Form 10-Q was filed with the SEC, reporting outstanding shares.
2026-05-28	First date of reported stock sales by Atlas XI and AVOF II.
2026-06-22	Date of reported stock sales by Atlas XI and AVOF II.
2026-06-23	Date of reported stock sales by Atlas XI and AVOF II.
2026-06-24	Date of reported stock sales by Atlas XI and AVOF II.
2026-07-02	Date of reported stock sales by Atlas XI and AVOF II.
2026-07-06	Last date of reported stock sales by Atlas XI and AVOF II.
2026-08-04	Date of the filing of Amendment No. 1 to Schedule 13D.

Recommendation

hold

The filing indicates significant selling pressure from major holders, which is a negative signal. However, without more context on the reasons for the sales (e.g., fund lifecycle, portfolio rebalancing vs. company-specific concerns) and Korro Bio's underlying business performance, a 'hold' recommendation is prudent. Investors should await further information or clarification before making a more definitive decision.

Keywords

Korro Bio, Schedule 13D, Common Stock, Insider Trading, Stock Sales, Atlas Venture, Beneficial Ownership, SEC Filing

Disclaimer:The information provided here is for general informational purposes only and does not constitute financial advice, recommendation, or endorsement of any kind. It may contain errors or omissions. You should not rely on this information to make financial decisions. Always seek the advice of a qualified financial professional before making any investment or financial decisions. Use of this information is at your own risk.