Officer Sale of Series A Common Stock

Amanda Whalen, Chief Financial Officer of Klaviyo, Inc., sold 14,000 shares of Series A Common Stock on June 18, 2026. The sale was executed as part of a Rule 10b5-1 trading plan. The shares were sold at a weighted average price of $13.23 per share, with individual transactions ranging from $13.12 to $13.49. Following the sale, Whalen owns 852,192 shares. The filing includes details about restricted stock units and performance stock units held by Whalen, which are part of the post-transaction share count. The transactions were reported on Form 4.