Form 4: Klaviyo CEO Sells Shares Under Pre-Arranged 10b5-1 Plan

Klaviyo CEO Andrew Bialecki sold 144,717 shares of Series A Common Stock for $27.76 per share, executed under a pre-arranged 10b5-1 trading plan.

Summary

• Andrew Bialecki, Klaviyo's Chief Executive Officer, Director, and 10% Owner, reported a change in beneficial ownership.
• On November 24, 2025, Mr. Bialecki converted 144,717 shares of Series B Common Stock into an equal number of Series A Common Stock.
• Immediately following the conversion, Mr. Bialecki sold all 144,717 shares of Series A Common Stock at a weighted average price of $27.76 per share.
• The shares were sold in multiple transactions with prices ranging from $27.39 to $28.20 per share.
• These transactions were executed pursuant to a Rule 10b5-1 trading plan adopted by Mr. Bialecki on May 20, 2025.
• Following these transactions, Mr. Bialecki directly owns 0 shares of Series A Common Stock and 73,700,896 shares of Series B Common Stock.
• Mr. Bialecki also holds indirect beneficial ownership of Series B Common Stock through various trusts: 7,517,410 shares via The Andrew P. Bialecki Grantor Retained Annuity Trust I of 2023, 517,006 shares via The Elizabeth L. Bialecki Irrevocable GST Trust of 2023, 517,006 shares via The Andrew P. Bialecki Irrevocable GST Trust of 2023, and 43,218 shares by his spouse.

Sentiment

Score: 5

Explanation: The sentiment is neutral. While an insider sale can sometimes be viewed negatively, the execution under a pre-arranged 10b5-1 plan mitigates concerns that the sale is based on new, adverse material information. The CEO retains significant ownership, particularly in Series B shares.

Positives

• The sale was executed under a Rule 10b5-1 trading plan, indicating a pre-scheduled and pre-approved transaction rather than a reaction to immediate company news or performance.
• The CEO retains substantial direct and indirect beneficial ownership of Klaviyo's Series B Common Stock, demonstrating continued alignment with shareholder interests.

Negatives

• The sale of 144,717 shares by the CEO, even if pre-planned, could be perceived negatively by some investors as a reduction in direct equity exposure.

Future Outlook

This Form 4 filing does not contain any forward-looking statements or guidance regarding the company's future performance or outlook.

Management Comments

• The Chief Executive Officer executed a pre-arranged sale of shares under a Rule 10b5-1 trading plan, adopted on May 20, 2025.

Industry Context

This insider transaction report is specific to Klaviyo and its CEO and does not provide broader industry context or trends.

Related Party Transactions

• Shares of Series B Common Stock are indirectly held by The Andrew P. Bialecki Grantor Retained Annuity Trust I of 2023, for which the Reporting Person serves as trustee.
• Shares of Series B Common Stock are indirectly held by The Elizabeth L. Bialecki Irrevocable GST Trust of 2023, for which the Reporting Person serves as a trustee.
• Shares of Series B Common Stock are indirectly held by The Andrew P. Bialecki Irrevocable GST Trust of 2023, for which the Reporting Person's spouse serves as a trustee.
• Shares of Series B Common Stock are indirectly held by the Reporting Person's spouse.

Stakeholder Impact

• Shareholders may interpret the CEO's sale of shares differently; however, the pre-planned nature via a 10b5-1 plan suggests a personal financial planning event rather than a reflection of company performance.
• The CEO's continued substantial direct and indirect ownership of Series B Common Stock indicates ongoing alignment with long-term company success.

Key Dates

Recommendation

The sale by Klaviyo's CEO was executed under a pre-arranged Rule 10b5-1 trading plan, which typically indicates a planned diversification or liquidity event rather than a reaction to new, adverse company developments. While insider sales can sometimes create negative sentiment, the pre-planned nature mitigates immediate concerns. The CEO retains a significant stake in the company through Series B shares. Investors should consider this as a routine insider transaction and continue to monitor company fundamentals and future disclosures for investment decisions.

Keywords

Klaviyo, KVYO, Andrew Bialecki, Insider Trading, Form 4, Stock Sale, 10b5-1 Plan, Beneficial Ownership, CEO