Klaviyo officer plans sale of 42,000 shares

Klaviyo executive Amanda Whalen filed a Rule 144 notice covering 42,000 KVYO shares, following earlier 10b5-1 plan sales.

Rhea-AI Filing Summary

Klaviyo, Inc. (KVYO) is the issuer for which officer Amanda Whalen has filed a notice of proposed sales of common stock under Rule 144. The notice covers 42,000 shares of common stock, with an indicated aggregate market value of $681,660.00, and notes prior 10b5‑1 plan sales over the past three months.

Key Figures

Shares to be sold under Rule 144: 42,000 shares Aggregate market value of shares to be sold: $681,660.00 Shares outstanding of same class: 126,937,933 shares +3 more

6 metrics

Shares to be sold under Rule 144 42,000 shares Common stock covered by the notice of proposed sale

Aggregate market value of shares to be sold $681,660.00 Value associated with the 42,000 Klaviyo common shares

Shares outstanding of same class 126,937,933 shares Total Klaviyo common shares outstanding of the same class

10b5-1 sale on June 18, 2026 14,000 shares for $185,194.80 Prior 3‑month 10b5‑1 plan sale of Klaviyo common stock

10b5-1 sale on July 16, 2026 14,000 shares for $248,508.40 Prior 3‑month 10b5‑1 plan sale of Klaviyo common stock

10b5-1 sale on August 14, 2026 14,000 shares for $258,633.20 Prior 3‑month 10b5‑1 plan sale of Klaviyo common stock

Key Terms

Rule 144, restricted stock units, 10b5-1, notice of proposed sale

4 terms

Rule 144 regulatory

"See the definition of "person" in paragraph (a) of Rule 144."

Rule 144 is a U.S. securities regulation that sets conditions under which restricted or insider-held shares can be legally resold to the public, such as required holding periods, availability of public information, limits on how much can be sold at once, and certain filing requirements. For investors it matters because it determines when previously locked-up shares can enter the market — like a release valve that can increase supply, affect share price, and signal insider intent.

restricted stock units financial

"The securities to be sold were acquired upon the vesting of restricted stock units"

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

10b5-1 regulatory

"10b5-1 Sales for AMANDA WHALEN 125 Summer Street"

A 10b5-1 plan is a pre-set schedule that lets company insiders buy or sell shares according to written instructions made when they do not possess material, nonpublic information. Think of it as a timed automatic payment for stock trades: it helps insiders avoid accusations of trading on secret information and gives outside investors a clearer signal about whether sales are routine or potentially informative about the company’s prospects.

notice of proposed sale regulatory

"information shall be given as to sales for the account of the person filing this notice."

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What does the Form 144 filing disclose for Klaviyo, Inc. (KVYO)?

The filing discloses that Amanda Whalen, an officer of Klaviyo, Inc., has filed a Rule 144 notice to sell 42,000 shares of common stock, with an indicated aggregate market value of $681,660.00, and provides details on prior related sales.

How many Klaviyo (KVYO) shares are covered by the new Rule 144 notice?

The notice covers 42,000 shares of Klaviyo, Inc. common stock. These securities are reported as having been acquired upon the vesting of restricted stock units during the period from November 15, 2025 through August 15, 2026.

What is the aggregate market value of KVYO shares in this Form 144?

The Form 144 lists an aggregate market value of $681,660.00 for the 42,000 Klaviyo common shares proposed to be sold. It also notes that there were 126,937,933 shares of the same class outstanding in total.

What prior 10b5-1 sales by Amanda Whalen in KVYO stock are disclosed?

The filing lists three 10b5‑1 plan sales of Klaviyo common stock by Amanda Whalen: 14,000 shares on June 18, 2026 for $185,194.80, 14,000 shares on July 16, 2026 for $248,508.40, and 14,000 shares on August 14, 2026 for $258,633.20.

How were the KVYO shares in this Form 144 acquired?

According to the remarks, the securities to be sold were acquired upon the vesting of restricted stock units during the period from November 15, 2025 through August 15, 2026. The class of securities is listed as common stock of Klaviyo, Inc.

What trading venue is referenced for the KVYO shares in this notice?

The notice identifies the class of securities as Klaviyo, Inc. common stock and specifies that the securities are traded on the NYSE. It also lists a broker, Morgan Stanley Smith Barney LLC Executive Financial Services, involved for the proposed sale of 42,000 shares.

What is the total number of KVYO shares outstanding mentioned in the Form 144?

The Form 144 states that there are 126,937,933 Klaviyo, Inc. common shares of the same class outstanding. This figure provides context and is separate from the 42,000 shares covered by the notice of proposed sale.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 09/17/2026 - 04:33 PM Accepted by SEC EDGAR 09/17/2026 - 04:33 PM Learn about SEC filing dates

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK	0001991131
Filer CCC	XXXXXXXX
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer	Klaviyo, Inc
SEC File Number	001-41806
Address of Issuer	125 Summer Street, 6th Floor Boston MASSACHUSETTS 02110
Phone	6172131788
Name of Person for Whose Account the Securities are To Be Sold	AMANDA WHALEN
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	Officer

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common	Morgan Stanley Smith Barney LLC Executive Financial Services 1 New York Plaza 8th Floor New York NY 10004	42000	681660.00	126937933	09/17/2026	NYSE

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common	11/15/2025	Restricted Stock Units	Issuer			42000	11/15/2025	N/A

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
10b5-1 Sales for AMANDA WHALEN 125 Summer Street, 6th Floor Boston MA 02110	Common	08/14/2026	14000	258633.20
10b5-1 Sales for AMANDA WHALEN 125 Summer Street, 6th Floor Boston MA 02110	Common	07/16/2026	14000	248508.40
10b5-1 Sales for AMANDA WHALEN 125 Summer Street, 6th Floor Boston MA 02110	Common	06/18/2026	14000	185194.80

144: Remarks and Signature

Remarks	The securities to be sold were acquired upon the vesting of restricted stock units during the period of 11/15/2025 through 8/15/2026
Date of Notice	09/17/2026
Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1	08/21/2025
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	/s/ Amanda Whalen
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)