System1 (SST) Form 4: 670 RSUs vested; 382 shares withheld

System1, Inc. (SST) reported an insider equity transaction by its General Counsel & Secretary, Daniel J. Weinrot.

Accepted by SEC EDGAR 10/17/2025 - 07:09 PM EDT Learn about SEC filing dates

Rhea-AI Filing Summary

System1, Inc. (SST) reported an insider equity transaction by its General Counsel & Secretary, Daniel J. Weinrot. On 10/15/2025, 670 restricted stock units vested, and the company withheld 382 shares at $7.94 under code F to cover tax withholding.

Following the transaction, the reporting person beneficially owned 70,196 shares. This figure includes 56,600 unvested RSUs, reflecting both vested holdings and remaining unvested awards.

Insider Trade Summary

Exercise Price or Tax Liability: 382 shares

Exercise Price or Tax Liability 1 txn

Insider Weinrot Daniel J

Role General Counsel & Secretary

Type	Security	Shares	Price	Value
Exercise Price or Tax Liability	Class A Common Stock	382	$7.94	$3K

Holdings After Transaction: Class A Common Stock — 70,196 shares (Direct)

Footnotes (2)

1. F1. Upon the vesting of 670 restricted stock units ("RSUs") previously granted to the reporting person, the Company withheld 382 shares to cover the reporting person's tax withholding obligation with respect to the vesting of such RSUs.
2. F2. Includes 56,600 unvested RSUs.

FAQ

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

What did System1 (SST) disclose in this Form 4?

An officer settled taxes on RSU vesting via share withholding of 382 shares at $7.94 on 10/15/2025.

How many RSUs vested for the System1 officer?

670 RSUs vested, as noted in the explanation of responses.

How many shares were withheld for taxes?

The company withheld 382 shares to satisfy tax obligations related to the RSU vesting.

What is the insider’s ownership after the transaction?

Beneficial ownership is 70,196 shares, which includes 56,600 unvested RSUs.

Who is the reporting person in this filing?

Daniel J. Weinrot, General Counsel & Secretary of System1, Inc.

What does transaction code F mean in this context?

Code F indicates shares were withheld by the issuer to cover taxes on equity award vesting.

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

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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^*

Weinrot Daniel J

(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)
	General Counsel & Secretary

3. Date of Earliest Transaction (Month/Day/Year)
10/15/2025

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	10/15/2025		F		382(1)	D	$7.94	70,196(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 670 restricted stock units ("RSUs") previously granted to the reporting person, the Company withheld 382 shares to cover the reporting person's tax withholding obligation with respect to the vesting of such RSUs.

2. Includes 56,600 unvested RSUs.

Remarks:

	/s/ Daniel J Weinrot	10/17/2025
	** 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.