Form 4: Summit Partners Divests 4 Million Shares of Klaviyo Series A Common Stock

Summit Partners, a significant 10% owner and director-affiliated entity, has sold 4 million shares of Klaviyo, Inc.'s Series A Common Stock for approximately $133.4 million after converting them from Series B shares.

Summary

• Summit Partners, L.P., along with several affiliated funds (Summit Partners Growth Equity Fund IX-A, L.P., Summit Partners Growth Equity Fund IX-B, L.P., Summit Partners Co-Invest (Kiwi), LP, SUMMIT INVESTORS GE IX/VC IV, LLC, and SUMMIT INVESTORS GE IX/VC IV (UK), L.P.), reported a change in beneficial ownership of Klaviyo, Inc. (KVYO) securities.
• On June 4, 2025, Summit Partners converted 4,000,000 shares of Series B Common Stock into an equal number of Series A Common Stock.
• Immediately following the conversion, Summit Partners disposed of these 4,000,000 shares of Series A Common Stock through a sale at a price of $33.35 per share.
• This transaction resulted in gross proceeds of approximately $133,400,000 from the sale of Series A Common Stock.
• After this transaction, Summit Partners and its affiliated entities beneficially own 30,827,778 shares of Series B Common Stock, which are convertible into Series A Common Stock.

Sentiment

Score: 3

Explanation: The sentiment is negative due to a significant insider sale by a major institutional investor, which can be interpreted as a lack of confidence or a strategic exit from a portion of their holding.

Negatives

• A significant sale of 4,000,000 shares by a 10% owner and director-affiliated entity like Summit Partners could be perceived negatively by the market, potentially signaling a lack of confidence or a strategic portfolio rebalancing.

Risks

• The market may react negatively to the news of a large insider sale, potentially leading to downward pressure on Klaviyo's stock price.
• Investor sentiment could be impacted if the sale is interpreted as a signal of reduced growth prospects or increased risk by a major institutional investor.

Future Outlook

This Form 4 filing does not contain any forward-looking statements or guidance regarding Klaviyo's future performance or outlook. It solely reports a past transaction by a beneficial owner.

Industry Context

Insider sales, particularly by large institutional investors or founders, are closely watched by the market as they can provide insights into the investor's perception of the company's valuation or future prospects. While this is a specific transaction for Klaviyo, it occurs within a broader context where investor confidence and capital allocation decisions are key drivers of stock performance in the software and marketing technology industry.

Related Party Transactions

• The reported transaction is a sale of shares by Summit Partners, L.P. and its affiliated funds, which are identified as a 10% owner and have director affiliations with Klaviyo, Inc. This constitutes a related party transaction under SEC rules.

Stakeholder Impact

• Shareholders: May experience negative sentiment and potential downward pressure on stock price due to the large insider sale.
• Investors: Will closely monitor this transaction as a data point regarding the confidence of a major institutional investor in Klaviyo's future.

Key Dates

Recommendation

Keywords

Klaviyo, KVYO, Summit Partners, SEC Form 4, Insider Trading, Stock Sale, Beneficial Ownership, Series A Common Stock, Series B Common Stock