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

Klaviyo Co-CEO Andrew Bialecki sold 140,646 shares of Series A Common Stock for approximately $3.85 million under a pre-arranged 10b5-1 trading plan.

Summary

• Andrew Bialecki, Co-Chief Executive Officer, Director, and 10% Owner of Klaviyo, Inc. (KVYO), reported transactions on January 13, 2026.
• The transactions involved the conversion of 140,646 shares of Series B Common Stock into Series A Common Stock.
• Subsequently, 140,646 shares of Series A Common Stock were sold in two separate transactions.
• The first sale involved 50,319 shares at a weighted average price of $27.62 per share, totaling approximately $1,389,899.58.
• The second sale involved 90,327 shares at a weighted average price of $27.29 per share, totaling approximately $2,464,099.83.
• The total value of Series A Common Stock sold was approximately $3,853,999.41.
• All transactions were executed pursuant to a Rule 10b5-1 trading plan adopted on May 20, 2025.
• Following these transactions, Mr. Bialecki directly holds 0 shares of Series A Common Stock.
• He continues to directly hold 69,274,090 shares of Series B Common Stock.
• Indirect holdings of Series B Common Stock through various trusts and a spouse total 8,594,640 shares.

Sentiment

Score: 5

Explanation: The sentiment is neutral. While insider selling can sometimes be viewed negatively, the execution under a pre-arranged 10b5-1 plan mitigates concerns about opportunistic trading. The Co-CEO retains substantial indirect holdings.

Positives

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

Negatives

• Insider selling, even under a 10b5-1 plan, can sometimes be perceived negatively by investors as it reduces the insider's direct equity stake in the company.
• The sale of 140,646 shares represents a reduction in direct beneficial ownership of Series A Common Stock to zero for the reporting person.

Risks

• Investor sentiment could be negatively impacted by the perception of insider selling, potentially leading to short-term stock price volatility.
• While the sale was planned, a significant reduction in direct holdings by a Co-CEO might raise questions about management's long-term confidence, despite the substantial remaining indirect holdings.

Future Outlook

The filing does not contain any forward-looking statements or guidance regarding the company's future performance or strategic direction.

Management Comments

• These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on May 20, 2025.
• The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

Industry Context

Insider sales under Rule 10b5-1 plans are a common practice among executives of publicly traded companies. These plans allow insiders to sell a predetermined number of shares at a predetermined time or price, providing liquidity and diversification while mitigating concerns about trading on material non-public information. Such sales are generally not indicative of a change in the company's fundamental performance or outlook.

Comparison to Industry Standards

• The use of a Rule 10b5-1 trading plan aligns with standard corporate governance practices for managing insider stock sales, providing a legal framework to avoid accusations of insider trading.
• Many executives across various industries utilize 10b5-1 plans for personal financial planning, such as diversification or funding personal expenses, without implying a negative outlook on their company's prospects.

Corporate Governance

Related Party Transactions

• Shares are held indirectly by the Andrew P. Bialecki Grantor Retained Annuity Trust I of 2023, of which the Reporting Person serves as trustee.
• Shares are held indirectly by the Elizabeth L. Bialecki Irrevocable GST Trust of 2023, of which the Reporting Person serves as a trustee.
• Shares are held indirectly by the Andrew P. Bialecki Irrevocable GST Trust of 2023, of which the Reporting Person's spouse serves as a trustee.
• Shares are held indirectly by the Reporting Person's spouse.
• The Reporting Person disclaims Section 16 beneficial ownership of shares held by the trusts except to the extent of his pecuniary interest therein.

Stakeholder Impact

• Shareholders may interpret the insider sale as a signal, potentially leading to short-term price fluctuations. However, the 10b5-1 plan context generally reduces negative implications.
• Employees: No direct impact mentioned, but general market sentiment can indirectly affect employee morale or stock-based compensation value.

Next Steps

• The filing does not explicitly mention any future actions, events, or milestones beyond the reported transactions.

Key Dates

Recommendation

The filing details a pre-planned insider sale by a Co-CEO under a Rule 10b5-1 plan. While insider selling can sometimes be a negative signal, the planned nature of these transactions, adopted well in advance, suggests personal financial management rather than a reaction to adverse company-specific news. The Co-CEO retains substantial indirect holdings. Therefore, this event alone does not warrant a change in investment thesis, and a 'hold' recommendation is appropriate, pending further company-specific or market developments.

Keywords

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