Statement of Changes in Beneficial Ownership (Form 4)

FORM 4 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 that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * Shea Thomas Anthony 2. Issuer Name and Ticker or Trading Symbol OneStream, Inc. [OS] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director __X__ 10% Owner __X__ Officer (give title below) _____ Other (specify below) CEO (Last) (First) (Middle) C/O ONESTREAM, INC., 191 N. CHESTER STREET 3. Date of Earliest Transaction (Month/Day/Year) 03/24/2026 (Street) BIRMINGHAM, MI 48009 4. If Amendment, Date 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 (City) (State) (Zip) 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

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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 Underlying Securities (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 of Derivative Security: 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
Class D Common Stock	$ 0	03/24/2026		G(1)			4,330,215	(2)	(2)	Class A Common Stock	4,330,215	$ 0	0 (3)	I	See footnote(4)
Class D Common Stock	$ 0	03/24/2026		G(1)		4,330,215		(2)	(2)	Class A Common Stock	4,330,215	$ 0	4,330,215	I	See Footnote(5)
Class D Common Stock	$ 0	03/25/2026		G(6)	V		4,330,215	(2)	(2)	Class A Common Stock	4,330,215	$ 0	0	I	See footnote(5)
Class D Common Stock	$ 0	03/25/2026		G(6)	V	4,330,215		(2)	(2)	Class A Common Stock	4,330,215	$ 0	11,856,018	I	See footnote(7)
Class D Common Stock	$ 0							(2)	(2)	Class A Common Stock	4,313,836		4,313,836(3)	D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Shea Thomas Anthony C/O ONESTREAM, INC. 191 N. CHESTER STREET BIRMINGHAM, MI 48009	X	X	CEO

Signatures

/s/ Holly Koczot, attorney-in-fact		03/26/2026
**Signature of Reporting Person		Date

Explanation of Responses:

*	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).
(1)	Represents a transfer of Class D Common Stock for no consideration from The Thomas A. Shea 2020 Annuity Trust dated December 23, 2020 (the "2020 Shea Annuity Trust") to the Thomas A Shea Remainder Trust dated December 23, 2020 (the "Shea Remainder Trust").
(2)	The Class D Common Stock is convertible at any time, at the holder's election, into Class A Common Stock on a 1:1 basis. Each outstanding share of Class D Common Stock will automatically convert into one share of Class A Common Stock upon the earlier of (i) any transfer, whether or not for value, except for certain transfers exempted by the Issuer's amended and restated certificate of incorporation, (ii) death or incapacity (if the holder is a natural person), provided that, with respect to the Reporting Person and his permitted transferees, conversion would be deferred for nine months following any such event, and (iii) the first trading day following the seventh anniversary of the Issuer's initial public offering.
(3)	On March 23, 2026, 419,787 shares of the Issuer's Class D Common Stock registered in the name of the 2020 Shea Annuity Trust were transferred to the Reporting Person.
(4)	Shares held of record by the 2020 Shea Annuity Trust. The Reporting Person's spouse serves as the trustee for the 2020 Shea Annuity Trust. By virtue of his relationship, the Reporting Person may be deemed to share voting and dispositive power with respect to the shares held by the 2020 Shea Annuity Trust.
(5)	Shares held of record by the Shea Remainder Trust. The Reporting Person's spouse serves as the co-trustee for the Shea Remainder Trust. By virtue of his relationship, the Reporting Person may be deemed to share voting and dispositive power with respect to the shares held by the Shea Remainder Trust.
(6)	Represents a transfer of Class D Common Stock for no consideration from the Shea Remainder Trust to the Shea Family Trust dated December 25, 2019 (the "2019 Shea Family Trust").
(7)	Shares held of record by the 2019 Shea Family Trust. The Reporting Person's spouse serves as the co-trustee for the 2019 Shea Family Trust. By virtue of his relationship, the Reporting Person may be deemed to share voting and dispositive power with respect to the shares held by the 2019 Shea Family Trust.

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