Bialecki Andrew - 26 May 2026 Form 4 Insider Report for Klaviyo, Inc. (KVYO)

Reporting relationship: Co-Chief Executive Officer, Director, 10%+ Owner
Issuer ticker: KVYO
Reported as of: 26 May 2026
Net transaction value: -$3,105,049
SEC form: 4
Accepted by SEC: 28 May 2026, 20:08:04 UTC
Prior SEC filing: 20 May 2026
Source filing: View source filing
Reporting owner signature: /s/ Landon Edmond, Attorney-in-Fact

Key filing fact

Bialecki Andrew filed Form 4 for Klaviyo, Inc. (KVYO) on 28 May 2026.

Key facts

This page summarizes Bialecki Andrew's Form 4 filing for Klaviyo, Inc. (KVYO).
3 reported transactions and 5 derivative rows are listed below.
Accepted by SEC: 28 May 2026, 20:08.

Change

Previous filing in this sequence was filed on 20 May 2026.
Current net transaction value: -$3,105,049.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001991099 Primary reporting owner

Bialecki Andrew

Relationship: Co-Chief Executive Officer, Director, 10%+ Owner
Address: C/O KLAVIYO, INC., 125 SUMMER STREET, 6TH FLOOR, BOSTON
Signature: /s/ Landon Edmond, Attorney-in-Fact
Signature date: 28 May 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

KVYO transaction

Series A Common Stock

Conversion of derivative security

Transaction value
Shares: +212,529
Change %
Price
Shares after: 212,529
Date: 26 May 2026
Ownership: Direct
Footnotes: F1, F2

KVYO transaction

Series A Common Stock

Sale

Transaction value: $3,105,049
Shares: -212,529
Change %: -100%
Price: $14.61
Shares after: 0
Date: 26 May 2026
Ownership: Direct
Footnotes: F1, F3

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

KVYO transaction Derivative

Series B Common Stock

Conversion of derivative security

Transaction value
Shares: -212,529
Change %: -0.32%
Price: $0.000000^*
Shares after: 66,731,589
Date: 26 May 2026
Ownership: Direct
Underlying class: Series A Common Stock
Underlying amount: 212,529
Exercise price
Footnotes: F1, F2

KVYO holding Derivative

Series B Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 7,517,410
Date: 26 May 2026
Ownership: By The Andrew P. Bialecki Grantor Retained Annuity Trust I of 2023
Underlying class: Series A Common Stock
Underlying amount: 7,517,410
Exercise price
Footnotes: F2, F4

KVYO holding Derivative

Series B Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 517,006
Date: 26 May 2026
Ownership: By The Elizabeth L. Bialecki Irrevocable GST Trust of 2023
Underlying class: Series A Common Stock
Underlying amount: 517,006
Exercise price
Footnotes: F2, F5

KVYO holding Derivative

Series B Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 517,006
Date: 26 May 2026
Ownership: By The Andrew P. Bialecki Irrevocable GST Trust of 2023
Underlying class: Series A Common Stock
Underlying amount: 517,006
Exercise price
Footnotes: F2, F6

KVYO holding Derivative

Series B Common Stock

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 43,218
Date: 26 May 2026
Ownership: By spouse
Underlying class: Series A Common Stock
Underlying amount: 43,218
Exercise price
Footnotes: F2

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Rule 10b5-1 trading plan

These transactions were reported as open-market trades under a Rule 10b5-1 plan. The plan lets an insider set trading instructions in advance, which can reduce the risk of trading while in possession of material nonpublic information.

Original filing language: transaction made pursuant to a contract, instruction, or written plan intended to satisfy Rule 10b5-1(c).

Explanation of responses 6 footnotes

Footnote F1

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.

Footnote F2

Each share of the Issuer's Series B Common Stock, par value $0.001 per share ("Series B Common Stock"), is convertible at any time at the option of the holder into one share of the Issuer's Series A Common Stock, par value $0.001 per share ("Series A Common Stock"), and will automatically convert into one share of Series A Common Stock upon the occurrence of certain events as set forth in the Issuer's certificate of incorporation. The Series B Common Stock has no expiration date.

Footnote F3

The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $14.43 to $15.00 per share. 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.

Footnote F4

Shares held by the Andrew P. Bialecki Grantor Retained Annuity Trust I of 2023, of which the Reporting Person serves as trustee. The Reporting Person disclaims Section 16 beneficial ownership of such shares except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed to be an admission that he has beneficial ownership of such shares for Section 16 or any other purpose.

Footnote F5

Shares held by the Elizabeth L. Bialecki Irrevocable GST Trust of 2023, of which the Reporting Person serves as a trustee. The Reporting Person disclaims Section 16 beneficial ownership of such shares except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed to be an admission that he has beneficial ownership of such shares for Section 16 or any other purpose.

Footnote F6

Shares held by the Andrew P. Bialecki Irrevocable GST Trust of 2023, of which the Reporting Person's spouse serves as a trustee. The Reporting Person disclaims Section 16 beneficial ownership of such shares except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed to be an admission that he has beneficial ownership of such shares for Section 16 or any other purpose.