Form 4: Klaviyo CEO Sells $7.5M in Stock Under 10b5-1 Plan

Klaviyo CEO Andrew Bialecki sold 211,358 shares of Series A Common Stock for approximately $7.5 million, pursuant to a pre-arranged 10b5-1 trading plan.

Summary

• Andrew Bialecki, Klaviyo's Chief Executive Officer, Director, and 10% Owner, reported transactions involving the company's stock.
• On September 23, 2025, Bialecki converted 211,358 shares of Series B Common Stock into an equal number of Series A Common Stock.
• Immediately following the conversion, he sold all 211,358 shares of Series A Common Stock in two separate transactions.
• The first sale involved 181,553 shares at a weighted average price of $35.52 per share, with prices ranging from $35.025 to $36.02.
• The second sale involved 29,805 shares at a weighted average price of $35.01 per share, with prices ranging from $35.00 to $35.02.
• These transactions were executed under a Rule 10b5-1 trading plan adopted by Bialecki on May 20, 2025.
• Following these transactions, Bialecki directly holds 74,593,469 shares of Series B Common Stock.
• Indirect holdings of Series B Common Stock include 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 held by his spouse.

Sentiment

Score: 4

Explanation: The sentiment is moderately negative due to significant insider selling by the CEO. While the 10b5-1 plan mitigates some of the negative implications by indicating a pre-planned sale, a large disposition by a key executive can still be viewed with caution by the market.

Positives

• The stock sales were conducted under a pre-arranged Rule 10b5-1 trading plan, indicating a planned and systematic approach to liquidity rather than an immediate reaction to market conditions.

Negatives

• The CEO, a significant insider and 10% owner, selling a substantial number of shares (211,358 shares) could be perceived negatively by investors, potentially signaling a lack of confidence or a desire to diversify personal holdings.

Risks

• Insider selling, particularly by a CEO, can sometimes lead to negative market sentiment and downward pressure on the stock price, as investors may interpret it as a signal about the company's future prospects.

Future Outlook

This Form 4 filing primarily reports past insider transactions and does not contain specific forward-looking statements or guidance regarding the company's future performance or strategic direction.

Industry Context

Insider selling is a common occurrence in the public markets, often driven by personal financial planning, diversification, or liquidity needs. While a CEO's sale of shares can sometimes raise questions, the execution under a Rule 10b5-1 plan is a standard practice designed to allow insiders to sell shares without concerns about trading on material non-public information, as the plan is established in advance.

Stakeholder Impact

• Shareholders may react to the CEO's stock sale, potentially leading to short-term negative sentiment or increased scrutiny of the company's performance and future outlook.
• The sale could be interpreted by some as a signal regarding the CEO's personal valuation of the company's stock, which might influence investor confidence.

Key Dates

Recommendation

While the CEO's sale of a significant number of shares could be a cause for concern, the execution under a pre-arranged 10b5-1 plan suggests a planned diversification or liquidity event rather than a reaction to adverse company-specific news. Without additional negative catalysts or changes in company fundamentals, this single insider transaction, while notable, does not warrant a 'sell' recommendation. Investors should 'hold' and monitor future company performance and additional insider activity.

Keywords

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