TapewireFind a company

person · Reporting owner

Whalen Amanda

Disclosed activity across 2 companies

Tapewire entity
21993
SEC CIK
0001991131

Export transaction history ↓

Reported relationships

Latest disclosed role at each company.

CompanyLast reported asReport datePublished
Klaviyo, Inc.KVYO · Entity 3775Chief Financial OfficerAugust 14, 2026August 19, 2026

Disclosed balances

About these balances

Latest available filing per company, not a reconstructed current portfolio. Matching sequences show the last reported balance with all source rows expandable; grouping alone does not establish account ownership. Do not add unresolved positions together. Filings may omit unchanged positions, and amendments may correct only part of an older disclosure. Jointly reported shares are not necessarily this owner's personal holdings.

Klaviyo, Inc.

Report date August 14, 2026 · Filed August 19, 2026

Security / awardOwnership accountDisclosed shares / unitsDisclosure context
Series A Common StockSEC Table I · non-derivativeDirect824,192 Reported balance After 2026-08-14 transaction · row 1 Account or security details depend on footnotes; rows are not merged.
1 source row

Row 1 · 2026-08-14 · Sale · Disposed 14,000 · Balance 824,192

F1: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025.

F2: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $18.25 to $18.82 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.

Series A Common StockSEC Table I · non-derivativeDirect795,242 Reported balance After 2026-08-15 transaction · row 2 Account or security details depend on footnotes; rows are not merged.
1 source row

Row 2 · 2026-08-15 · Tax withholding · Disposed 28,950 · Balance 795,242

F3: Represents shares of the Issuer's Series A Common Stock, par value $0.001 per share ("Series A Common Stock") withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of restricted stock units ("RSUs").

F4: Consists of (i) 89,917 shares of Series A Common Stock; (ii) 478,053 unvested RSUs awarded under the Issuer's 2023 Stock Option and Incentive Plan (the "Plan"), each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement; and (iii) 227,272 unvested performance stock units awarded under the Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement.

Filing footnotes · ownership attribution and instrument terms

F1: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025.

F2: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $18.25 to $18.82 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.

F3: Represents shares of the Issuer's Series A Common Stock, par value $0.001 per share ("Series A Common Stock") withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of restricted stock units ("RSUs").

F4: Consists of (i) 89,917 shares of Series A Common Stock; (ii) 478,053 unvested RSUs awarded under the Issuer's 2023 Stock Option and Incentive Plan (the "Plan"), each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement; and (iii) 227,272 unvested performance stock units awarded under the Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement.

Past disclosures · reporting ended (1)

No longer tracked through insider filings. These historical balances do not imply present ownership or a zero position.

Taylor Morrison Home Corp

Report date July 24, 2026 · Filed July 27, 2026

Section 16 reporting ended · disclosed 2026-07-27. Current position is not established by this disclosure.

Security / awardOwnership accountDisclosed shares / unitsDisclosure context
Deferred Stock UnitsSEC Table II · derivative / convertible securityDirect0 Reported balance After 2026-07-24 transaction · row 1 Instrument identity requires review; Table II rows are not merged.
1 source row

Row 1 · 2026-07-24 · Disposition to issuer · Disposed 3,287 · Balance 0

F1: Each deferred stock unit ("DSU") represents a contingent right to receive one share of common stock, par value $0.00001 per share, of Taylor Morrison Home Corporation (the "Issuer"). On July 24, 2026, Berkshire Hathaway Inc. ("BHI") acquired the Issuer pursuant to an Agreement and Plan of Merger, dated as of May 31, 2026 (the "Merger Agreement"), by and among the Issuer, BHI and WXYZ Merger Sub, Inc., a wholly owned subsidiary of BHI ("Merger Sub"). In accordance with the Merger Agreement, Merger Sub merged with and into the Issuer (the "Merger") with the Issuer surviving the Merger as a wholly owned subsidiary of BHI. At the effective time of the Merger, each outstanding DSU became immediately vested, was cancelled and converted into the right to receive an amount in cash equal to (x) the number of shares subject to such DSU as of immediately prior to the Effective Time, multiplied by (y) $72.50.

Filing footnotes · ownership attribution and instrument terms

F1: Each deferred stock unit ("DSU") represents a contingent right to receive one share of common stock, par value $0.00001 per share, of Taylor Morrison Home Corporation (the "Issuer"). On July 24, 2026, Berkshire Hathaway Inc. ("BHI") acquired the Issuer pursuant to an Agreement and Plan of Merger, dated as of May 31, 2026 (the "Merger Agreement"), by and among the Issuer, BHI and WXYZ Merger Sub, Inc., a wholly owned subsidiary of BHI ("Merger Sub"). In accordance with the Merger Agreement, Merger Sub merged with and into the Issuer (the "Merger") with the Issuer surviving the Merger as a wholly owned subsidiary of BHI. At the effective time of the Merger, each outstanding DSU became immediately vested, was cancelled and converted into the right to receive an amount in cash equal to (x) the number of shares subject to such DSU as of immediately prior to the Effective Time, multiplied by (y) $72.50.

Transaction history

JSON API
Reset

Purchases/sales include open-market and private transactions. Plan disclosure applies to the filing; individual rows may differ. “Not disclosed” is not “unplanned.”

The cutoff filters transaction history only. Company summaries and owner relationships show the latest available disclosures. Parser corrections can improve historical records.

Transaction dateCompanyActivity / securityShares / unitsReported priceReported valueDetails
August 15, 2026 Filed Aug 19, 2026 00:02 UTC Klaviyo, Inc. KVYO · Entity 3775 Tax withholdingSeries A Common Stock 28,950 $18.49 $535,285.50
Disclosure

SEC source: 0001470831-26-000839 · wk-form4_1787097772.xml · nonDerivative · entry 2

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 795,242

F3 · kind: Represents shares of the Issuer's Series A Common Stock, par value $0.001 per share ("Series A Common Stock") withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of restricted stock units ("RSUs").

F4 · balance_after: Consists of (i) 89,917 shares of Series A Common Stock; (ii) 478,053 unvested RSUs awarded under the Issuer's 2023 Stock Option and Incentive Plan (the "Plan"), each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement; and (iii) 227,272 unvested performance stock units awarded under the Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement.

Read SEC document
August 14, 2026 Filed Aug 19, 2026 00:02 UTC Klaviyo, Inc. KVYO · Entity 3775 SaleSeries A Common Stock 14,000 $18.47 $258,580.00
Disclosure

SEC source: 0001470831-26-000839 · wk-form4_1787097772.xml · nonDerivative · entry 1

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 824,192

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025.

F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $18.25 to $18.82 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.

Read SEC document
July 24, 2026 Filed Jul 27, 2026 20:15 UTC Taylor Morrison Home Corp TMHC · Entity 28500 Disposition to issuerDeferred Stock Units · Derivative 3,287 $72.50 $238,307.50
Disclosure

SEC source: 0001193125-26-318111 · ownership.xml · derivative · entry 1

Whalen Amanda · CIK 0001991131 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 3,287 shares

Expires not disclosed

F1 · derivative.exercise_price: Each deferred stock unit ("DSU") represents a contingent right to receive one share of common stock, par value $0.00001 per share, of Taylor Morrison Home Corporation (the "Issuer"). On July 24, 2026, Berkshire Hathaway Inc. ("BHI") acquired the Issuer pursuant to an Agreement and Plan of Merger, dated as of May 31, 2026 (the "Merger Agreement"), by and among the Issuer, BHI and WXYZ Merger Sub, Inc., a wholly owned subsidiary of BHI ("Merger Sub"). In accordance with the Merger Agreement, Merger Sub merged with and into the Issuer (the "Merger") with the Issuer surviving the Merger as a wholly owned subsidiary of BHI. At the effective time of the Merger, each outstanding DSU became immediately vested, was cancelled and converted into the right to receive an amount in cash equal to (x) the number of shares subject to such DSU as of immediately prior to the Effective Time, multiplied by (y) $72.50.

F1 · kind: Each deferred stock unit ("DSU") represents a contingent right to receive one share of common stock, par value $0.00001 per share, of Taylor Morrison Home Corporation (the "Issuer"). On July 24, 2026, Berkshire Hathaway Inc. ("BHI") acquired the Issuer pursuant to an Agreement and Plan of Merger, dated as of May 31, 2026 (the "Merger Agreement"), by and among the Issuer, BHI and WXYZ Merger Sub, Inc., a wholly owned subsidiary of BHI ("Merger Sub"). In accordance with the Merger Agreement, Merger Sub merged with and into the Issuer (the "Merger") with the Issuer surviving the Merger as a wholly owned subsidiary of BHI. At the effective time of the Merger, each outstanding DSU became immediately vested, was cancelled and converted into the right to receive an amount in cash equal to (x) the number of shares subject to such DSU as of immediately prior to the Effective Time, multiplied by (y) $72.50.

F1 · price: Each deferred stock unit ("DSU") represents a contingent right to receive one share of common stock, par value $0.00001 per share, of Taylor Morrison Home Corporation (the "Issuer"). On July 24, 2026, Berkshire Hathaway Inc. ("BHI") acquired the Issuer pursuant to an Agreement and Plan of Merger, dated as of May 31, 2026 (the "Merger Agreement"), by and among the Issuer, BHI and WXYZ Merger Sub, Inc., a wholly owned subsidiary of BHI ("Merger Sub"). In accordance with the Merger Agreement, Merger Sub merged with and into the Issuer (the "Merger") with the Issuer surviving the Merger as a wholly owned subsidiary of BHI. At the effective time of the Merger, each outstanding DSU became immediately vested, was cancelled and converted into the right to receive an amount in cash equal to (x) the number of shares subject to such DSU as of immediately prior to the Effective Time, multiplied by (y) $72.50.

F1 · derivative.exercise_date: Each deferred stock unit ("DSU") represents a contingent right to receive one share of common stock, par value $0.00001 per share, of Taylor Morrison Home Corporation (the "Issuer"). On July 24, 2026, Berkshire Hathaway Inc. ("BHI") acquired the Issuer pursuant to an Agreement and Plan of Merger, dated as of May 31, 2026 (the "Merger Agreement"), by and among the Issuer, BHI and WXYZ Merger Sub, Inc., a wholly owned subsidiary of BHI ("Merger Sub"). In accordance with the Merger Agreement, Merger Sub merged with and into the Issuer (the "Merger") with the Issuer surviving the Merger as a wholly owned subsidiary of BHI. At the effective time of the Merger, each outstanding DSU became immediately vested, was cancelled and converted into the right to receive an amount in cash equal to (x) the number of shares subject to such DSU as of immediately prior to the Effective Time, multiplied by (y) $72.50.

F1 · derivative.expiration_date: Each deferred stock unit ("DSU") represents a contingent right to receive one share of common stock, par value $0.00001 per share, of Taylor Morrison Home Corporation (the "Issuer"). On July 24, 2026, Berkshire Hathaway Inc. ("BHI") acquired the Issuer pursuant to an Agreement and Plan of Merger, dated as of May 31, 2026 (the "Merger Agreement"), by and among the Issuer, BHI and WXYZ Merger Sub, Inc., a wholly owned subsidiary of BHI ("Merger Sub"). In accordance with the Merger Agreement, Merger Sub merged with and into the Issuer (the "Merger") with the Issuer surviving the Merger as a wholly owned subsidiary of BHI. At the effective time of the Merger, each outstanding DSU became immediately vested, was cancelled and converted into the right to receive an amount in cash equal to (x) the number of shares subject to such DSU as of immediately prior to the Effective Time, multiplied by (y) $72.50.

Read SEC document
July 16, 2026 Filed Jul 18, 2026 00:01 UTC Klaviyo, Inc. KVYO · Entity 3775 SaleSeries A Common Stock 14,000 $17.75 $248,500.00
Disclosure

SEC source: 0001470831-26-000720 · wk-form4_1784332874.xml · nonDerivative · entry 1

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 838,192

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025.

F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $17.43 to $18.05 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.

F3 · balance_after: Consists of (i) 59,302 shares of the Issuer's Series A Common Stock, par value $0.001 per share ("Series A Common Stock"); (ii) 551,618 unvested restricted stock units awarded under the Issuer's 2023 Stock Option and Incentive Plan (the "Plan"), each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement; and (iii) 227,272 unvested performance stock units awarded under the Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement.

Read SEC document
June 18, 2026 Filed Jun 19, 2026 00:08 UTC Klaviyo, Inc. KVYO · Entity 3775 SaleSeries A Common Stock 14,000 $13.23 $185,220.00
Disclosure

SEC source: 0001470831-26-000561 · wk-form4_1781827722.xml · nonDerivative · entry 1

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 852,192

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025.

F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $13.12 to $13.49 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.

F3 · balance_after: Consists of (i) 73,302 shares of the Issuer's Series A Common Stock, par value $0.001 per share ("Series A Common Stock"); (ii) 551,618 unvested restricted stock units awarded under the Issuer's 2023 Stock Option and Incentive Plan (the "Plan"), each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement; and (iii) 227,272 unvested performance stock units awarded under the Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement.

Read SEC document
May 21, 2026 Filed May 26, 2026 22:10 UTC Taylor Morrison Home Corp TMHC · Entity 28500 GrantDeferred Stock Units · Derivative 3,287 Not disclosed Not disclosed
Disclosure

SEC source: 0001193125-26-239816 · ownership.xml · derivative · entry 1

Whalen Amanda · CIK 0001991131 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 3,287

Underlying: Common Stock · 3,287 shares

Expires not disclosed

F1 · derivative.exercise_price: Each deferred stock unit represents a contingent right to receive one share of Common Stock. The deferred stock units shall be vested upon the earlier of (i) the first anniversary of the date of grant and (ii) the date of the Company's annual meeting of stockholders immediately following the date of grant. The deferred stock units will be settled in shares of Common Stock upon the earlier of (i) the reporting person's separation from service on the Company's board of directors or (ii) a change in control.

F2 · price: The deferred stock units were acquired by Ms. Whalen pursuant to the terms of the Company's Non-Employee Director Deferred Compensation Plan, under which directors may elect to defer their annual equity award granted pursuant to the Taylor Morrison 2013 Omnibus Equity Award Plan, as amended.

F1 · derivative.exercise_date: Each deferred stock unit represents a contingent right to receive one share of Common Stock. The deferred stock units shall be vested upon the earlier of (i) the first anniversary of the date of grant and (ii) the date of the Company's annual meeting of stockholders immediately following the date of grant. The deferred stock units will be settled in shares of Common Stock upon the earlier of (i) the reporting person's separation from service on the Company's board of directors or (ii) a change in control.

F1 · derivative.expiration_date: Each deferred stock unit represents a contingent right to receive one share of Common Stock. The deferred stock units shall be vested upon the earlier of (i) the first anniversary of the date of grant and (ii) the date of the Company's annual meeting of stockholders immediately following the date of grant. The deferred stock units will be settled in shares of Common Stock upon the earlier of (i) the reporting person's separation from service on the Company's board of directors or (ii) a change in control.

Read SEC document
May 15, 2026 Filed May 19, 2026 00:08 UTC Klaviyo, Inc. KVYO · Entity 3775 ConversionSeries B Common Stock · Derivative 13,527 $0.00 $0.00
Disclosure

SEC source: 0001470831-26-000455 · wk-form4_1779149319.xml · derivative · entry 6

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 269,585

Underlying: Series A Common Stock · 13,527 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: 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.

F4 · kind: Represents 13,527 shares of Series B Common Stock automatically converted into shares of Series A Common Stock in connection with tax withholding obligations related to the vesting and settlement of restricted stock units ("RSUs").

F2 · derivative.exercise_date: 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.

F2 · derivative.expiration_date: 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.

F7 · balance_after: Consists of 269,585 shares of Series B Common Stock.

Read SEC document
May 15, 2026 Filed May 19, 2026 00:08 UTC Klaviyo, Inc. KVYO · Entity 3775 Tax withholdingSeries A Common Stock 42,476 $14.38 $610,804.88
Disclosure

SEC source: 0001470831-26-000455 · wk-form4_1779149319.xml · nonDerivative · entry 4

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 866,192

F5 · kind: Represents shares of Series A Common Stock withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of RSUs.

F6 · balance_after: Consists of (i) 87,302 shares of Series A Common Stock; (ii) 551,618 unvested RSUs awarded under the Issuer's 2023 Stock Option and Incentive Plan (the "Plan"), each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement; and (iii) 227,272 unvested performance stock units awarded under the Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement.

Read SEC document
May 15, 2026 Filed May 19, 2026 00:08 UTC Klaviyo, Inc. KVYO · Entity 3775 ConversionSeries A Common Stock 13,527 Not disclosed Not disclosed
Disclosure

SEC source: 0001470831-26-000455 · wk-form4_1779149319.xml · nonDerivative · entry 3

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 908,668

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F4 · kind: Represents 13,527 shares of Series B Common Stock automatically converted into shares of Series A Common Stock in connection with tax withholding obligations related to the vesting and settlement of restricted stock units ("RSUs").

F2 · price: 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.

Read SEC document
May 14, 2026 Filed May 19, 2026 00:08 UTC Klaviyo, Inc. KVYO · Entity 3775 ConversionSeries B Common Stock · Derivative 14,000 $0.00 $0.00
Disclosure

SEC source: 0001470831-26-000455 · wk-form4_1779149319.xml · derivative · entry 5

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 283,112

Underlying: Series A Common Stock · 14,000 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: 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.

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025.

F2 · derivative.exercise_date: 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.

F2 · derivative.expiration_date: 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.

Read SEC document
May 14, 2026 Filed May 19, 2026 00:08 UTC Klaviyo, Inc. KVYO · Entity 3775 SaleSeries A Common Stock 14,000 $14.26 $199,640.00
Disclosure

SEC source: 0001470831-26-000455 · wk-form4_1779149319.xml · nonDerivative · entry 2

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 895,141

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025.

F3 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $13.88 to $14.45 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.

Read SEC document
May 14, 2026 Filed May 19, 2026 00:08 UTC Klaviyo, Inc. KVYO · Entity 3775 ConversionSeries A Common Stock 14,000 Not disclosed Not disclosed
Disclosure

SEC source: 0001470831-26-000455 · wk-form4_1779149319.xml · nonDerivative · entry 1

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 909,141

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025.

F2 · price: 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.

Read SEC document
April 16, 2026 Filed Apr 18, 2026 00:10 UTC Klaviyo, Inc. KVYO · Entity 3775 ConversionSeries B Common Stock · Derivative 4,293 $0.00 $0.00
Disclosure

SEC source: 0001470831-26-000380 · wk-form4_1776471055.xml · derivative · entry 5

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 297,112

Underlying: Series A Common Stock · 4,293 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F5 · derivative.exercise_price: 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 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.

F4 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025.

F5 · derivative.exercise_date: 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 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.

F5 · derivative.expiration_date: 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 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.

F8 · balance_after: Consists of (i) 262,737 shares of Series B Common Stock and (ii) 34,375 unvested RSUs awarded under the Issuer's 2015 Stock Incentive Plan, each representing the contingent right to receive one share of Series B Common Stock upon vesting and settlement.

Read SEC document
April 16, 2026 Filed Apr 18, 2026 00:10 UTC Klaviyo, Inc. KVYO · Entity 3775 SaleSeries A Common Stock 14,000 $18.54 $259,560.00
Disclosure

SEC source: 0001470831-26-000380 · wk-form4_1776471055.xml · nonDerivative · entry 4

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 895,141

F4 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025.

F6 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $18.34 to $18.98 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.

F7 · balance_after: Consists of (i) 42,687 shares of Series A Common Stock; (ii) 625,182 unvested RSUs awarded under the Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement; and (iii) 227,272 unvested PSUs awarded under the Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement.

Read SEC document
April 16, 2026 Filed Apr 18, 2026 00:10 UTC Klaviyo, Inc. KVYO · Entity 3775 ConversionSeries A Common Stock 4,293 Not disclosed Not disclosed
Disclosure

SEC source: 0001470831-26-000380 · wk-form4_1776471055.xml · nonDerivative · entry 3

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 909,141

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F4 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025.

F5 · price: 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 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.

Read SEC document
April 15, 2026 Filed Apr 18, 2026 00:10 UTC Klaviyo, Inc. KVYO · Entity 3775 GrantSeries A Common Stock 227,272 $0.00 $0.00
Disclosure

SEC source: 0001470831-26-000380 · wk-form4_1776471055.xml · nonDerivative · entry 2

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 904,848

F2 · shares: Represents performance stock units ("PSUs") awarded under the Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement. The PSUs will vest in up to three tranches over a two-year measurement period, subject to the achievement of specified performance targets tied to the trading price of the Series A Common Stock and the Reporting Person's continued service in the same or substantially equivalent position as the Reporting Person held as of the grant date through the applicable vesting date. Each tranche of PSUs will vest only if the average closing price of the Series A Common Stock for a period of at least sixty consecutive calendar days is at or above a specified dollar value during the applicable measurement period.

F3 · shares: (continued) The stock price targets for tranches 1 through 3 are $30.00, $50.00, and $75.00 per share, respectively, subject to proportionate adjustment in the event of any stock split or other similar change in the Issuer's capital stock.

Read SEC document
April 15, 2026 Filed Apr 18, 2026 00:10 UTC Klaviyo, Inc. KVYO · Entity 3775 GrantSeries A Common Stock 265,151 $0.00 $0.00
Disclosure

SEC source: 0001470831-26-000380 · wk-form4_1776471055.xml · nonDerivative · entry 1

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 677,576

F1 · shares: Represents restricted stock units ("RSUs") awarded under the Issuer's 2023 Stock Option and Incentive Plan (the "Plan"), each representing the contingent right to receive one share of the Issuer's Series A Common Stock, par value $0.001 per share ("Series A Common Stock"), upon vesting and settlement. The RSUs vest as follows: (i) 50% of the RSUs will vest in eight equal quarterly installments, with the first such installment vesting on May 15, 2026, and (ii) thereafter the remaining 50% of the RSUs will vest in four equal quarterly installments, subject to the Reporting Person's continued service on each such vesting date.

Read SEC document
March 12, 2026 Filed Mar 13, 2026 23:57 UTC Klaviyo, Inc. KVYO · Entity 3775 SaleSeries A Common Stock 5,077 $19.34 $98,189.18
Disclosure

SEC source: 0001470831-26-000270 · wk-form4_1773446269.xml · nonDerivative · entry 2

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 412,425

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025.

F3 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $19.27 to $19.38 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.

F4 · balance_after: Consists of (i) 52,394 shares of the Issuer's Series A Common Stock, par value $0.001 per share ("Series A Common Stock"), and (ii) 360,031 unvested restricted stock units awarded under the Issuer's 2023 Stock Option and Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement.

Read SEC document
March 12, 2026 Filed Mar 13, 2026 23:57 UTC Klaviyo, Inc. KVYO · Entity 3775 SaleSeries A Common Stock 8,923 $19.72 $175,961.56
Disclosure

SEC source: 0001470831-26-000270 · wk-form4_1773446269.xml · nonDerivative · entry 1

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 417,502

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025.

F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $19.385 to $20.38 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.

Read SEC document
February 15, 2026 Filed Feb 18, 2026 21:12 UTC Klaviyo, Inc. KVYO · Entity 3775 ConversionSeries B Common Stock · Derivative 29,513 $0.00 $0.00
Disclosure

SEC source: 0001470831-26-000157 · wk-form4_1771449150.xml · derivative · entry 7

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 301,405

Underlying: Series A Common Stock · 29,513 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: 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.

F5 · kind: Represents 29,513 shares of Series B Common Stock automatically converted into shares of Series A Common Stock in connection with tax withholding obligations related to the vesting and settlement of restricted stock units ("RSUs").

F2 · derivative.exercise_date: 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.

F2 · derivative.expiration_date: 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.

F8 · balance_after: Consists of (i) 267,030 shares of Series B Common Stock and (ii) 34,375 unvested RSUs awarded under the Issuer's 2015 Stock Incentive Plan, each representing the contingent right to receive one share of Series B Common Stock upon vesting and settlement.

Read SEC document
February 15, 2026 Filed Feb 18, 2026 21:12 UTC Klaviyo, Inc. KVYO · Entity 3775 Tax withholdingSeries A Common Stock 45,307 $18.60 $842,710.20
Disclosure

SEC source: 0001470831-26-000157 · wk-form4_1771449150.xml · nonDerivative · entry 5

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 426,425

F6 · kind: Represents shares of Series A Common Stock withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of RSUs.

F7 · balance_after: Consists of (i) 66,394 shares of Series A Common Stock and (ii) 360,031 unvested RSUs awarded under the Issuer's 2023 Stock Option and Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement.

Read SEC document
February 15, 2026 Filed Feb 18, 2026 21:12 UTC Klaviyo, Inc. KVYO · Entity 3775 ConversionSeries A Common Stock 29,513 Not disclosed Not disclosed
Disclosure

SEC source: 0001470831-26-000157 · wk-form4_1771449150.xml · nonDerivative · entry 4

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 471,732

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F5 · kind: Represents 29,513 shares of Series B Common Stock automatically converted into shares of Series A Common Stock in connection with tax withholding obligations related to the vesting and settlement of restricted stock units ("RSUs").

F2 · price: 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.

Read SEC document
February 13, 2026 Filed Feb 18, 2026 21:12 UTC Klaviyo, Inc. KVYO · Entity 3775 ConversionSeries B Common Stock · Derivative 14,000 $0.00 $0.00
Disclosure

SEC source: 0001470831-26-000157 · wk-form4_1771449150.xml · derivative · entry 6

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 330,918

Underlying: Series A Common Stock · 14,000 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: 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.

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025.

F2 · derivative.exercise_date: 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.

F2 · derivative.expiration_date: 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.

Read SEC document
February 13, 2026 Filed Feb 18, 2026 21:12 UTC Klaviyo, Inc. KVYO · Entity 3775 SaleSeries A Common Stock 4,719 $18.63 $87,914.97
Disclosure

SEC source: 0001470831-26-000157 · wk-form4_1771449150.xml · nonDerivative · entry 3

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 442,219

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025.

F4 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $18.52 to $18.75 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.

Read SEC document
February 13, 2026 Filed Feb 18, 2026 21:12 UTC Klaviyo, Inc. KVYO · Entity 3775 SaleSeries A Common Stock 9,281 $19.01 $176,431.81
Disclosure

SEC source: 0001470831-26-000157 · wk-form4_1771449150.xml · nonDerivative · entry 2

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 446,938

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025.

F3 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $18.76 to $19.75 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.

Read SEC document
February 13, 2026 Filed Feb 18, 2026 21:12 UTC Klaviyo, Inc. KVYO · Entity 3775 ConversionSeries A Common Stock 14,000 Not disclosed Not disclosed
Disclosure

SEC source: 0001470831-26-000157 · wk-form4_1771449150.xml · nonDerivative · entry 1

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 456,219

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025.

F2 · price: 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.

Read SEC document
January 15, 2026 Filed Jan 16, 2026 21:06 UTC Klaviyo, Inc. KVYO · Entity 3775 ConversionSeries B Common Stock · Derivative 4,045 $0.00 $0.00
Disclosure

SEC source: 0001470831-26-000041 · wk-form4_1768597559.xml · derivative · entry 4

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 344,918

Underlying: Series A Common Stock · 4,045 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: 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.

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025.

F2 · derivative.exercise_date: 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.

F2 · derivative.expiration_date: 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.

F6 · balance_after: Consists of (i) 235,543 shares of Series B Common Stock and (ii) 109,375 unvested RSUs awarded under the Issuer's 2015 Stock Incentive Plan, each representing the contingent right to receive one share of Series B Common Stock upon vesting and settlement.

Read SEC document
January 15, 2026 Filed Jan 16, 2026 21:06 UTC Klaviyo, Inc. KVYO · Entity 3775 SaleSeries A Common Stock 6,174 $25.52 $157,560.48
Disclosure

SEC source: 0001470831-26-000041 · wk-form4_1768597559.xml · nonDerivative · entry 3

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 442,219

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025.

F4 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $25.295 to $25.68 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.

F5 · balance_after: Consists of (i) 42,687 shares of Series A Common Stock and (ii) 399,532 unvested restricted stock units ("RSUs") awarded under the Issuer's 2023 Stock Option and Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement.

Read SEC document
January 15, 2026 Filed Jan 16, 2026 21:06 UTC Klaviyo, Inc. KVYO · Entity 3775 SaleSeries A Common Stock 7,826 $26.08 $204,102.08
Disclosure

SEC source: 0001470831-26-000041 · wk-form4_1768597559.xml · nonDerivative · entry 2

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 448,393

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025.

F3 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $25.78 to $26.73 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.

Read SEC document
January 15, 2026 Filed Jan 16, 2026 21:06 UTC Klaviyo, Inc. KVYO · Entity 3775 ConversionSeries A Common Stock 4,045 Not disclosed Not disclosed
Disclosure

SEC source: 0001470831-26-000041 · wk-form4_1768597559.xml · nonDerivative · entry 1

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 456,219

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025.

F2 · price: 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.

Read SEC document
December 18, 2025 Filed Dec 19, 2025 21:06 UTC Klaviyo, Inc. KVYO · Entity 3775 SaleSeries A Common Stock 460 $30.59 $14,071.40
Disclosure

SEC source: 0001470831-25-000444 · wk-form4_1766178380.xml · nonDerivative · entry 2

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 452,174

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025.

F3 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $30.45 to $30.63 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.

F4 · balance_after: Consists of (i) 52,642 shares of the Issuer's Series A Common Stock, par value $0.001 per share ("Series A Common Stock"), and (ii) 399,532 unvested restricted stock units awarded under the Issuer's 2023 Stock Option and Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement.

Read SEC document
December 18, 2025 Filed Dec 19, 2025 21:06 UTC Klaviyo, Inc. KVYO · Entity 3775 SaleSeries A Common Stock 13,540 $31.41 $425,291.40
Disclosure

SEC source: 0001470831-25-000444 · wk-form4_1766178380.xml · nonDerivative · entry 1

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 452,634

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 21, 2025.

F2 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $30.64 to $31.63 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.

Read SEC document
November 15, 2025 Filed Nov 18, 2025 21:07 UTC Klaviyo, Inc. KVYO · Entity 3775 ConversionSeries B Common Stock · Derivative 29,513 $0.00 $0.00
Disclosure

SEC source: 0001470831-25-000332 · wk-form4_1763500027.xml · derivative · entry 7

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 348,963

Underlying: Series A Common Stock · 29,513 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: 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.

F5 · kind: Represents 29,513 shares of Series B Common Stock automatically converted into shares of Series A Common Stock in connection with tax withholding obligations related to the vesting and settlement of restricted stock units ("RSUs").

F2 · derivative.exercise_date: 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.

F2 · derivative.expiration_date: 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.

F8 · balance_after: Consists of (i) 239,588 shares of Series B Common Stock and (ii) 109,375 unvested RSUs awarded under the Issuer's 2015 Stock Incentive Plan, each representing the contingent right to receive one share of Series B Common Stock upon vesting and settlement.

Read SEC document
November 15, 2025 Filed Nov 18, 2025 21:07 UTC Klaviyo, Inc. KVYO · Entity 3775 Tax withholdingSeries A Common Stock 45,058 $28.61 $1,289,109.38
Disclosure

SEC source: 0001470831-25-000332 · wk-form4_1763500027.xml · nonDerivative · entry 5

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 466,174

F6 · kind: Represents shares of Series A Common Stock withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of RSUs.

F7 · balance_after: Consists of (i) 66,642 shares of Series A Common Stock and (ii) 399,532 unvested RSUs awarded under the Issuer's 2023 Stock Option and Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement.

Read SEC document
November 15, 2025 Filed Nov 18, 2025 21:07 UTC Klaviyo, Inc. KVYO · Entity 3775 ConversionSeries A Common Stock 29,513 Not disclosed Not disclosed
Disclosure

SEC source: 0001470831-25-000332 · wk-form4_1763500027.xml · nonDerivative · entry 4

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 511,232

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F5 · kind: Represents 29,513 shares of Series B Common Stock automatically converted into shares of Series A Common Stock in connection with tax withholding obligations related to the vesting and settlement of restricted stock units ("RSUs").

F2 · price: 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.

Read SEC document
November 14, 2025 Filed Nov 18, 2025 21:07 UTC Klaviyo, Inc. KVYO · Entity 3775 ConversionSeries B Common Stock · Derivative 15,000 $0.00 $0.00
Disclosure

SEC source: 0001470831-25-000332 · wk-form4_1763500027.xml · derivative · entry 6

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 378,476

Underlying: Series A Common Stock · 15,000 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: 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.

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 16, 2024.

F2 · derivative.exercise_date: 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.

F2 · derivative.expiration_date: 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.

Read SEC document
November 14, 2025 Filed Nov 18, 2025 21:07 UTC Klaviyo, Inc. KVYO · Entity 3775 SaleSeries A Common Stock 300 $27.89 $8,367.00
Disclosure

SEC source: 0001470831-25-000332 · wk-form4_1763500027.xml · nonDerivative · entry 3

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 481,719

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 16, 2024.

F4 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $27.805 to $27.95 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.

Read SEC document
November 14, 2025 Filed Nov 18, 2025 21:07 UTC Klaviyo, Inc. KVYO · Entity 3775 SaleSeries A Common Stock 14,700 $28.61 $420,567.00
Disclosure

SEC source: 0001470831-25-000332 · wk-form4_1763500027.xml · nonDerivative · entry 2

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 482,019

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 16, 2024.

F3 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $27.96 to $28.95 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.

Read SEC document
November 14, 2025 Filed Nov 18, 2025 21:07 UTC Klaviyo, Inc. KVYO · Entity 3775 ConversionSeries A Common Stock 15,000 Not disclosed Not disclosed
Disclosure

SEC source: 0001470831-25-000332 · wk-form4_1763500027.xml · nonDerivative · entry 1

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 496,719

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 16, 2024.

F2 · price: 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.

Read SEC document
October 10, 2025 Filed Oct 10, 2025 21:36 UTC Klaviyo, Inc. KVYO · Entity 3775 ConversionSeries B Common Stock · Derivative 15,000 $0.00 $0.00
Disclosure

SEC source: 0001470831-25-000254 · wk-form4_1760132172.xml · derivative · entry 4

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 393,476

Underlying: Series A Common Stock · 15,000 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: 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.

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 16, 2024.

F2 · derivative.exercise_date: 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.

F2 · derivative.expiration_date: 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.

F6 · balance_after: Consists of (i) 209,101 shares of Series B Common Stock and (ii) 184,375 unvested RSUs awarded under the Issuer's 2015 Stock Incentive Plan, each representing the contingent right to receive one share of Series B Common Stock upon vesting and settlement.

Read SEC document
October 10, 2025 Filed Oct 10, 2025 21:36 UTC Klaviyo, Inc. KVYO · Entity 3775 SaleSeries A Common Stock 5,192 $24.45 $126,944.40
Disclosure

SEC source: 0001470831-25-000254 · wk-form4_1760132172.xml · nonDerivative · entry 3

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 481,719

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 16, 2024.

F4 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $24.25 to $24.73 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.

F5 · balance_after: Consists of (i) 42,687 shares of Series A Common Stock and (ii) 439,032 unvested restricted stock units ("RSUs") awarded under the Issuer's 2023 Stock Option and Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement.

Read SEC document
October 10, 2025 Filed Oct 10, 2025 21:36 UTC Klaviyo, Inc. KVYO · Entity 3775 SaleSeries A Common Stock 9,808 $25.33 $248,436.64
Disclosure

SEC source: 0001470831-25-000254 · wk-form4_1760132172.xml · nonDerivative · entry 2

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 486,911

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 16, 2024.

F3 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $24.93 to $25.85 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.

Read SEC document
October 10, 2025 Filed Oct 10, 2025 21:36 UTC Klaviyo, Inc. KVYO · Entity 3775 ConversionSeries A Common Stock 15,000 Not disclosed Not disclosed
Disclosure

SEC source: 0001470831-25-000254 · wk-form4_1760132172.xml · nonDerivative · entry 1

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 496,719

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 16, 2024.

F2 · price: 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.

Read SEC document
September 12, 2025 Filed Sep 12, 2025 22:10 UTC Klaviyo, Inc. KVYO · Entity 3775 ConversionSeries B Common Stock · Derivative 11,204 $0.00 $0.00
Disclosure

SEC source: 0001470831-25-000197 · wk-form4_1757714997.xml · derivative · entry 3

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 408,476

Underlying: Series A Common Stock · 11,204 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: 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.

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 16, 2024.

F2 · derivative.exercise_date: 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.

F2 · derivative.expiration_date: 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.

F5 · balance_after: Consists of (i) 224,101 shares of Series B Common Stock and (ii) 184,375 unvested RSUs awarded under the Issuer's 2015 Stock Incentive Plan, each representing the contingent right to receive one share of Series B Common Stock upon vesting and settlement.

Read SEC document
September 12, 2025 Filed Sep 12, 2025 22:10 UTC Klaviyo, Inc. KVYO · Entity 3775 SaleSeries A Common Stock 15,000 $31.50 $472,500.00
Disclosure

SEC source: 0001470831-25-000197 · wk-form4_1757714997.xml · nonDerivative · entry 2

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 481,719

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 16, 2024.

F3 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $31.17 to $31.98 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.

F4 · balance_after: Consists of (i) 42,687 shares of Series A Common Stock and (ii) 439,032 unvested restricted stock units ("RSUs") awarded under the Issuer's 2023 Stock Option and Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement.

Read SEC document
September 12, 2025 Filed Sep 12, 2025 22:10 UTC Klaviyo, Inc. KVYO · Entity 3775 ConversionSeries A Common Stock 11,204 Not disclosed Not disclosed
Disclosure

SEC source: 0001470831-25-000197 · wk-form4_1757714997.xml · nonDerivative · entry 1

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 496,719

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 16, 2024.

F2 · price: 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.

Read SEC document
August 15, 2025 Filed Aug 20, 2025 00:51 UTC Klaviyo, Inc. KVYO · Entity 3775 ConversionSeries B Common Stock · Derivative 29,513 $0.00 $0.00
Disclosure

SEC source: 0001470831-25-000142 · wk-form4_1755651065.xml · derivative · entry 4

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 419,680

Underlying: Series A Common Stock · 29,513 shares

Expires not disclosed

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F2 · derivative.exercise_price: Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of 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.

F1 · kind: Represents 29,513 shares of the Issuer's Series B Common Stock, par value $0.001 per share ("Series B Common Stock"), automatically converted into shares of the Issuer's Series A Common Stock, par value $0.001 per share ("Series A Common Stock"), in connection with tax withholding obligations related to the vesting and settlement of restricted stock units ("RSUs").

F2 · derivative.exercise_date: Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of 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.

F2 · derivative.expiration_date: Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of 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.

F7 · balance_after: Consists of (i) 235,305 shares of Series B Common Stock and (ii) 184,375 unvested RSUs awarded under the Issuer's 2015 Stock Incentive Plan, each representing the contingent right to receive one share of Series B Common Stock upon vesting and settlement.

Read SEC document
August 15, 2025 Filed Aug 20, 2025 00:51 UTC Klaviyo, Inc. KVYO · Entity 3775 SaleSeries A Common Stock 15,000 $31.32 $469,800.00
Disclosure

SEC source: 0001470831-25-000142 · wk-form4_1755651065.xml · nonDerivative · entry 3

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 485,515

F4 · kind: These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 16, 2024.

F5 · price: The price reported in Column 4 is a weighted average price. The shares were sold in multiple transactions at prices ranging from $30.92 to $31.53 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.

F6 · balance_after: Consists of (i) 46,483 shares of Series A Common Stock and (ii) 439,032 unvested RSUs awarded under the Issuer's 2023 Stock Option and Incentive Plan, each representing the contingent right to receive one share of Series A Common Stock upon vesting and settlement.

Read SEC document
August 15, 2025 Filed Aug 20, 2025 00:51 UTC Klaviyo, Inc. KVYO · Entity 3775 Tax withholdingSeries A Common Stock 46,829 $31.43 $1,471,835.47
Disclosure

SEC source: 0001470831-25-000142 · wk-form4_1755651065.xml · nonDerivative · entry 2

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 500,515

F3 · kind: Represents shares of the Series A Common Stock withheld by the Issuer to satisfy tax withholding obligations in connection with the vesting and settlement of RSUs.

Read SEC document
August 15, 2025 Filed Aug 20, 2025 00:51 UTC Klaviyo, Inc. KVYO · Entity 3775 ConversionSeries A Common Stock 29,513 Not disclosed Not disclosed
Disclosure

SEC source: 0001470831-25-000142 · wk-form4_1755651065.xml · nonDerivative · entry 1

Whalen Amanda · CIK 0001991131 · Chief Financial Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 547,344

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · kind: Represents 29,513 shares of the Issuer's Series B Common Stock, par value $0.001 per share ("Series B Common Stock"), automatically converted into shares of the Issuer's Series A Common Stock, par value $0.001 per share ("Series A Common Stock"), in connection with tax withholding obligations related to the vesting and settlement of restricted stock units ("RSUs").

F2 · price: Each share of Series B Common Stock is convertible at any time at the option of the holder into one share of 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.

Read SEC document

Value uses the disclosed total when available, otherwise shares × reported transaction price. It is not an estimate of exercise cash cost or investment performance.