OS Insider Sale: CFO Disposes 8,943 Shares Under 10b5-1 Plan

Rhea-AI Filing Summary

OneStream, Inc. Chief Financial Officer William A. Koefoed reported a sale of 8,943 shares of Class A common stock on 09/15/2025 at a price of $19.03 per share. After the transaction he beneficially owned 221,983 shares; the reported total includes unvested restricted stock units. The filing notes the sales were effected under a Rule 10b5-1 trading plan adopted by the reporting person on February 21, 2025. The Form 4 was signed on behalf of Mr. Koefoed and dated 09/16/2025.

Positive

• Transaction was executed under a Rule 10b5-1 trading plan, which clarifies timing and intent of the sale
• Filing discloses inclusion of unvested restricted stock units in the beneficial ownership total, improving transparency
• Form 4 filed promptly and signed by attorney-in-fact, meeting disclosure requirements

Negative

• Reporting person sold 8,943 shares, reducing direct beneficial ownership
• Remaining beneficial ownership includes unvested RSUs, which are subject to vesting conditions and not immediately liquid

Insights

Securities Analyst

TL;DR: Officer executed a pre-established plan to sell a modest number of shares; disclosure is routine and non-eventful.

The reported sale of 8,943 shares at $19.03 under a Rule 10b5-1 plan indicates the transaction was pre-authorized, reducing ambiguity about insider timing. The remaining beneficial ownership of 221,983 shares (including unvested RSUs) is disclosed explicitly. For investors, the filing provides clear, required transparency but does not itself signal a material corporate development.

Corporate Governance Expert

TL;DR: Filing meets Section 16 disclosure requirements and documents use of an approved trading plan.

The Form 4 identifies the reporting person as the Chief Financial Officer and documents the Rule 10b5-1 plan adoption date, which is best practice for insider transactions. Disclosure that the beneficial ownership figure includes unvested restricted stock units adds helpful clarity about the composition of holdings. No amendments or irregularities are reported.

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
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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^*

Koefoed William A

(Last) (First) (Middle)

C/O ONESTREAM, INC.

191 N. CHESTER STREET

(Street)

BIRMINGHAM MI 48009

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
OneStream, Inc. [ OS ]

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)
09/15/2025

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	09/15/2025		S(1)		8,943	D	$19.03	221,983(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. The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on February 21, 2025.

2. The shares reported include unvested restricted stock units.

	/s/ Holly Koczot, attorney-in-fact	09/16/2025
	** 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 insider transaction did OneStream (OS) report on this Form 4?

William A. Koefoed sold 8,943 shares of Class A common stock on 09/15/2025 at $19.03 per share, as reported on the Form 4.

Was the sale by the OneStream insider pre‑authorized?

Yes. The sale was effected pursuant to a Rule 10b5-1 trading plan adopted on February 21, 2025.

How many shares does the reporting person beneficially own after the sale?

221,983 shares beneficially owned following the reported transaction; this total includes unvested restricted stock units.

What is the reporting person's role at OneStream?

William A. Koefoed is identified as the Chief Financial Officer (Officer) in the Form 4.

When was the Form 4 signed and filed?

The Form 4 is dated 09/16/2025 and bears a signature by an attorney-in-fact on that date.