SST insider filing: CFO RSU vest triggers 263-share tax withholding

Rhea-AI Filing Summary

System1, Inc. (SST) reported an insider transaction by its Chief Financial Officer, Tridivesh Kidambi. On 10/28/2025, the company withheld 263 shares of Class A common stock at $6.18 per share to satisfy taxes due upon the vesting of 625 RSUs previously granted to the officer (transaction code F).

Following the withholding, the officer beneficially owned 120,509 shares, which includes 54,814 unvested RSUs. This filing reflects administrative tax withholding rather than an open-market sale.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider Kidambi Tridivesh

Role Chief Financial Officer

Type	Security	Shares	Price	Value
Tax Withholding	Class A Common Stock	263	$6.18	$2K

Holdings After Transaction: Class A Common Stock — 120,509 shares (Direct)

Footnotes (1)

1. Upon the vesting of 625 restricted stock units ("RSUs") previously granted to the reporting person, the Company withheld 263 shares to cover the reporting person's tax withholding obligation with respect to the vesting of such RSUs. Includes 54,814 unvested RSUs.

Form 4 Insider Transactions: What Each Field Means →

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).

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^*

Kidambi Tridivesh

(Last) (First) (Middle)

4235 REDWOOD AVE

(Street)

LOS ANGELES CA 90066

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
System1, Inc. [ SST ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
10/28/2025

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
Class A Common Stock	10/28/2025		F		263(1)	D	$6.18	120,509(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. Upon the vesting of 625 restricted stock units ("RSUs") previously granted to the reporting person, the Company withheld 263 shares to cover the reporting person's tax withholding obligation with respect to the vesting of such RSUs.

2. Includes 54,814 unvested RSUs.

Remarks:

	/s/ Daniel Weinrot, Attorney-in-Fact for Tridivesh Kidambi	10/30/2025
	** 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 did System1 (SST) disclose in this Form 4?

The CFO reported an administrative tax withholding of 263 shares on 10/28/2025 tied to RSU vesting.

Was this an open-market sale of SST shares?

No. The code F entry reflects shares withheld by the company to cover taxes on RSU vesting.

How many RSUs vested for the CFO?

The filing states 625 RSUs vested, triggering the tax withholding.

At what price were the withheld shares valued?

The shares were valued at $6.18 per share for withholding purposes.

How many shares does the CFO own after this transaction?

Beneficial ownership is 120,509 shares, including 54,814 unvested RSUs.

What is the relationship of the reporting person to System1 (SST)?

The reporting person is the Chief Financial Officer of System1.