Form 4: Klaviyo CEO Sells $7.3M in Stock Under 10b5-1 Plan

Klaviyo CEO Andrew Bialecki executed a pre-arranged sale of 226,382 Series A Common Stock shares totaling approximately $7.3 million.

Summary

• Andrew Bialecki, Klaviyo's Chief Executive Officer, Director, and 10% Owner, reported stock transactions on September 16, 2025.
• He converted 226,382 shares of Series B Common Stock into an equal number of Series A Common Stock shares.
• Subsequently, he sold 140,921 shares of Series A Common Stock at a weighted average price of $32.71 per share, with prices ranging from $32.02 to $33.01.
• An additional 85,461 shares of Series A Common Stock were sold at a weighted average price of $31.76 per share, with prices ranging from $31.32 to $32.01.
• The total value of the Series A Common Stock sold was approximately $7,329,990.27.
• These transactions were conducted pursuant to a Rule 10b5-1 trading plan adopted by Mr. Bialecki on May 20, 2025.
• Following these reported transactions, Mr. Bialecki directly holds 0 shares of Series A Common Stock.
• He continues to directly hold 74,804,827 shares of Series B Common Stock.
• Indirect beneficial ownership of Series B Common Stock is also reported through The Andrew P. Bialecki Grantor Retained Annuity Trust I of 2023, The Elizabeth L. Bialecki Irrevocable GST Trust of 2023, The Andrew P. Bialecki Irrevocable GST Trust of 2023, and by his spouse.

Sentiment

Score: 5

Explanation: The filing is a factual report of insider transactions. While a large sale by a CEO could be seen negatively, the disclosure that it was part of a pre-arranged 10b5-1 plan mitigates immediate negative sentiment, making it neutral to slightly negative depending on market interpretation.

Positives

• The transactions were executed under a pre-arranged Rule 10b5-1 trading plan, indicating a planned and systematic approach to stock sales rather than a reactive decision.

Negatives

• A significant sale of shares by the CEO and a 10% owner, even if pre-planned, could be perceived negatively by some investors, potentially leading to short-term market speculation.

Risks

• Potential for negative market perception due to a large insider sale, which could exert downward pressure on the company's stock price in the short term.

Future Outlook

N/A

Industry Context

N/A

Stakeholder Impact

• Shareholders may react to the sale of a significant number of shares by the CEO and a 10% owner, potentially influencing short-term stock price movements.

Key Dates

Keywords

Klaviyo, KVYO, Insider Trading, Form 4, Stock Sale, CEO, Andrew Bialecki, 10b5-1 Plan, Series A Common Stock, Series B Common Stock