KVYO Insider Sale: Director Disposes 3,413 Shares Under 10b5-1 Plan

Rhea-AI Filing Summary

Susan St. Ledger, a director of Klaviyo, Inc. (KVYO), sold 3,413 shares of the issuer's Series A Common Stock on 09/10/2025 at $32.20 per share under a Rule 10b5-1 trading plan adopted June 11, 2025. After the reported sale she beneficially owns 10,939 shares, composed of 5,119 vested Series A shares and 5,820 unvested restricted stock units that convert to one share each upon vesting. The sale was reported on a Form 4 and executed through an attorney-in-fact.

Positive

• Sale executed under a Rule 10b5-1 trading plan, which supports compliance and reduces insider-timing concerns
• Form 4 discloses composition of beneficial ownership (vested shares plus unvested RSUs), improving transparency

Negative

• Director reduced direct holdings by 3,413 shares, which may be viewed negatively by some investors
• Unclear proportional impact because total outstanding shares and percentage ownership are not provided

Insights

Financial Analyst

TL;DR: Director sale under a pre-established 10b5-1 plan; ownership remains meaningful due to unvested RSUs.

The reported disposition of 3,413 shares at $32.20 appears to be a routine, pre-planned sale under a Rule 10b5-1 plan, which typically reduces concerns about opportunistic insider timing. Post-transaction beneficial ownership of 10,939 shares includes 5,820 unvested RSUs, indicating continued alignment with shareholder interests subject to vesting. The transaction size relative to total outstanding shares is not provided, so market-impact assessment is limited.

Corporate Governance Expert

TL;DR: Disclosure follows Section 16 reporting norms and cites an affirmative defense trading plan.

The Form 4 discloses a sale pursuant to a 10b5-1 plan adopted June 11, 2025, which provides the director with an affirmative defense against insider trading claims if plan conditions are met. Reporting the mix of vested shares and unvested RSUs is good governance practice, clarifying what portion of holdings remains contingent. No information about changes to compensation or additional grants is included.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

X

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

St. Ledger Susan

(Last) (First) (Middle)

C/O KLAVIYO, INC.

125 SUMMER STREET, 6TH FLOOR

(Street)

BOSTON MA 02110

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Klaviyo, Inc. [ KVYO ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
09/10/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Series A Common Stock	09/10/2025		S(1)		3,413	D	$32.2	10,939(2)	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. These transactions were effected by the Reporting Person pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on June 11, 2025.

2. Consists of (i) 5,119 shares of the Issuer's Series A Common Stock, par value $0.001 per share ("Series A Common Stock"), and (ii) 5,820 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.

Remarks:

	/s/ Landon Edmond, Attorney-in-Fact	09/12/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What transaction did Susan St. Ledger report for Klaviyo (KVYO)?

The report discloses a sale of 3,413 shares of Series A Common Stock executed on 09/10/2025 at $32.20 per share.

Was the sale part of a pre-established trading plan for KVYO insiders?

Yes. The transactions were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on June 11, 2025.

How many shares does Susan St. Ledger beneficially own after the reported sale?

She beneficially owns 10,939 shares following the transaction, consisting of 5,119 vested shares and 5,820 unvested restricted stock units.

Do the reported holdings include unvested equity awards?

Yes. The beneficial ownership includes 5,820 unvested restricted stock units, each representing the right to one share upon vesting.

Does the Form 4 indicate any other derivative or option transactions?

No. The Form 4 contains no entries in the derivative securities section; only a non-derivative sale of Series A common stock is reported.