John Kinzer - 19 Dec 2025 Form 4 Insider Report for OneStream, Inc. (OS)

Role: Director, Strategic Advisor
Signature: /s/ Holly Koczot, attorney-in-fact
Issuer symbol: OS
Transactions as of: 19 Dec 2025
Net transactions value: $0
Form type: 4
Filing time: 23 Dec 2025, 16:12:10 UTC
Previous filing: 04 Dec 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Kinzer John	Director, Strategic Advisor	C/O ONESTREAM, INC., 191 N. CHESTER STREET, BIRMINGHAM	/s/ Holly Koczot, attorney-in-fact	23 Dec 2025	0001621078

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	OS	Class A Common Stock	Conversion of derivative security		+30,000			30,000	19 Dec 2025	See Footnote	F1, F2
holding	OS	Class A Common Stock						101,737	19 Dec 2025	Direct	F3

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	OS	Common Units	Conversion of derivative security	$0	-30,000	-10%	$0.000000	270,997	19 Dec 2025	Class D Common Stock	30,000		See Footnote	F2, F4, F5
transaction	OS	Class D Common Stock	Conversion of derivative security	$0	+30,000		$0.000000	30,000	19 Dec 2025	Class A Common Stock	30,000		See Footnote	F2, F4, F6
transaction	OS	Class D Common Stock	Conversion of derivative security	$0	-30,000	-100%	$0.000000	0	19 Dec 2025	Class A Common Stock	30,000		See Footnote	F1, F2, F6

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	The Class A Common Stock was acquired upon the conversion, at the holder's election, of Class D Common Stock held by the holder on a 1:1 basis.
F2	The shares are held by the John E. Kinzer Trust, of which the Reporting Person is a trustee.
F3	The shares reported include unvested restricted stock units.
F4	On December 19, 2025, the holder redeemed 30,000 Common Units of OneStream Software LLC, and 30,000 shares of the holder's Class C Common Stock were cancelled, in exchange for 30,000 shares of Class D Common Stock.
F5	The Common Units may be redeemed by the holder for shares of Class D Common Stock on a 1:1 basis, and an equal number of the holder's shares of Class C Common Stock (which have no economic rights) will be cancelled in connection with the redemption. The Common Units have no expiration date.
F6	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), and (iii) the first trading day following the seventh anniversary of the Issuer's initial public offering.