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

Klaviyo's Co-Chief Executive Officer, Andrew Bialecki, sold a total of 154,153 shares of Series A Common Stock in early January 2026, pursuant to a pre-arranged Rule 10b5-1 trading plan.

Summary

• Andrew Bialecki, Co-CEO, Director, and 10% Owner of Klaviyo, Inc., executed sales of Series A Common Stock.
• On January 6, 2026, 137,504 shares of Series B Common Stock were converted to Series A Common Stock, followed by the sale of 135,122 shares at a weighted average price of $28.92 and 2,382 shares at $28.52.
• On January 7, 2026, an additional 16,649 shares of Series B Common Stock were converted to Series A Common Stock, and subsequently sold at a weighted average price of $30.01.
• All transactions were conducted under a Rule 10b5-1 trading plan adopted on May 20, 2025.
• Following these reported transactions, Andrew Bialecki's direct beneficial ownership of Series A Common Stock is 0.
• He retains significant indirect beneficial ownership of Series B Common Stock through various trusts and his spouse, totaling 8,594,640 shares, though he disclaims Section 16 beneficial ownership for most of these.

Sentiment

Score: 5

Explanation: The sentiment is neutral. While insider selling can be perceived negatively, the execution under a pre-arranged 10b5-1 plan mitigates concerns that the sales are based on new, adverse material non-public information. It represents a planned liquidity event.

Positives

• The sales were executed under a pre-arranged Rule 10b5-1 trading plan, indicating a planned liquidity event rather than a reaction to new, negative company information.

Negatives

• Insider selling, even under a 10b5-1 plan, can sometimes be perceived negatively by the market as it reduces the insider's direct equity stake.

Future Outlook

The filing does not contain any forward-looking statements or guidance.

Industry Context

This Form 4 filing reports routine insider transactions and does not provide information directly related to broader industry trends or competitive landscape. Insider sales under a 10b5-1 plan are common for executives seeking to diversify their holdings or manage personal finances.

Related Party Transactions

• Andrew Bialecki holds indirect beneficial ownership of Series B Common Stock through the Andrew P. Bialecki Grantor Retained Annuity Trust I of 2023 (7,517,410 shares), the Elizabeth L. Bialecki Irrevocable GST Trust of 2023 (517,006 shares), the Andrew P. Bialecki Irrevocable GST Trust of 2023 (517,006 shares), and by his spouse (43,218 shares). He disclaims Section 16 beneficial ownership for these shares except to the extent of his pecuniary interest.

Stakeholder Impact

• Shareholders may view the insider selling with slight caution, though the 10b5-1 plan context reduces the negative signal. The transactions do not directly impact employees, customers, suppliers, or creditors.

Key Dates

Recommendation

The insider sales by Co-CEO Andrew Bialecki were conducted under a pre-established Rule 10b5-1 trading plan, which typically indicates a planned diversification or liquidity event rather than a reaction to negative company-specific news. While insider selling can sometimes be a bearish signal, the context of a 10b5-1 plan generally renders it a neutral event for investment decisions. Without additional information on company performance or strategic developments, these routine insider transactions alone do not warrant a change in investment posture, hence a 'hold' recommendation.

Keywords

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