[Form 4] Klaviyo, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Atlas Venture funds have filed Amendment No. 1 to their Schedule 13D for ImageneBio, Inc. (formerly Ikena Oncology, Nasdaq: IKNA) to report dilution of their holdings after the 1-for-12 reverse stock split and completion of Ikena’s all-stock merger with Inmagene on 25 Jul 2025.

• Collectively, the reporting entities now own 418,179 post-split common shares, equal to 3.6 % of the 11.6 million shares outstanding.
• Breakdown: Fund X 241,800 shares (2.1 %), Fund XI 103,494 shares (0.9 %), Opportunity Fund I 72,885 shares (0.6 %).
• All voting and dispositive powers are shared among the respective limited partnerships and their general partners; no sole voting power is reported.
• The funds ceased to be 5 % beneficial owners on 25 Jul 2025; no purchases or sales occurred in the past 60 days.
• Purpose: administrative update reflecting dilution from the merger and reverse split; Atlas Venture continues to hold the same absolute number of economic shares pre-transaction but a lower percentage.

Atlas Venture disclaims group status among the reporting persons. A joint filing agreement is included as Exhibit 99.1.

Positive

• No insider selling: Atlas Venture did not dispose of any shares, signalling continued support for ImageneBio.
• Merger completion and reverse split finalized, providing corporate clarity after the Inmagene transaction.

Negative

• Ownership dilution: Atlas Venture’s combined stake falls below 5 %, slightly reducing insider alignment.
• Lower reporting threshold: Future 13D filings may cease unless ownership rises again, reducing visibility into a key holder’s changes.

Insights

Financial Analyst

TL;DR – Atlas Venture’s stake falls to 3.6 % due to merger-related dilution; no shares sold, impact on IKNA share supply already known.

The amendment is largely administrative. Atlas Venture’s absolute share count is unchanged, but the completed Inmagene merger and 1-for-12 reverse split expanded the denominator, cutting their ownership below the 5 % 13D threshold. The filing removes a potential overhang concern of insider selling, as none occurred. From a governance lens, the reduced concentration slightly broadens the float, but Atlas remains a meaningful holder. Market impact is likely minimal because the share count change was disclosed in the July 25 reverse-split announcement and already reflected in trading. Overall, neutral for valuation and liquidity.

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).

1. Name and Address of Reporting Person^*

Shopify Strategic Holdings 3 LLC

(Last) (First) (Middle)

103 FOULK ROAD, SUITE 218-A

(Street)

WILMINGTON DE 19803

(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)

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

3. Date of Earliest Transaction (Month/Day/Year)
07/28/2025

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

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

	Form filed by One Reporting Person
X	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

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
Warrants to Purchase Series B Common Stock (Right to Buy)	$0.01	07/28/2025		X			344,383	(1)	07/28/2032	Series B Common Stock	344,383	$0	2,755,057	D(2)
Series B Common Stock	(3)	07/28/2025		X		344,383		(3)	(3)	Series A Common Stock	344,383	$0.01	15,939,963	D(2)

1. Name and Address of Reporting Person^*

Shopify Strategic Holdings 3 LLC

(Last) (First) (Middle)

103 FOULK ROAD, SUITE 218-A

(Street)

WILMINGTON DE 19803

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

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

1. Name and Address of Reporting Person^*

SHOPIFY INC.

(Last) (First) (Middle)

151 O'CONNOR STREET

GROUND FLOOR

(Street)

OTTAWA A6 K2P 2L8

(City) (State) (Zip)

Relationship of Reporting Person(s) to Issuer

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

Explanation of Responses:

1. 25% of the shares subject to the warrants vested on July 28, 2022, and the remaining shares vest quarterly in equal amounts through July 28, 2027. Notwithstanding the foregoing, in connection with the Issuer's initial public offering ("IPO"), 25% of the total number of shares subject to the warrants vested immediately prior to the completion of the IPO.

2. Reflects securities held directly by Shopify Strategic Holdings 3 LLC, a wholly-owned subsidiary of Shopify Inc. ("Shopify"). Shopify is an indirect beneficial owner and disclaims beneficial ownership except to the extent of its pecuniary interest therein.

3. 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 of the Issuer, and will automatically convert into 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.

	SHOPIFY STRATEGIC HOLDINGS 3 LLC, By: /s/ Jason Kilpela, Director	07/29/2025
	SHOPIFY INC, By: /s/ Michael L. Johnson, Corporate Secretary	07/29/2025
	** Signature of Reporting Person	Date
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FAQ

Why did Atlas Venture file an amended Schedule 13D for IKNA?

To report that its percentage ownership fell to 3.6 % after IKNA’s merger with Inmagene and a 1-for-12 reverse split on 25 Jul 2025.

How many IKNA shares does Atlas Venture now own?

Collectively 418,179 shares: Fund X 241,800; Fund XI 103,494; Opportunity Fund I 72,885.

Did Atlas Venture sell any IKNA shares?

No. The filing states no purchases or sales occurred in the past 60 days; dilution alone lowered the percentage.

What is IKNA’s new share count after the merger?

The filing references approximately 11.6 million common shares outstanding as of 25 Jul 2025.

Does Atlas Venture still have voting control over its IKNA shares?

Yes. Each fund and its general partners retain shared voting and dispositive power over their respective shares.