Champlain Investment Partners reveals 3.3% OneStream (OS) stake in Schedule 13G

Rhea-AI Filing Summary

Champlain Investment Partners, LLC filed a Schedule 13G reporting a passive ownership stake in OneStream, Inc. common stock. Champlain reports beneficial ownership of 2,886,232 shares, representing 3.3% of the outstanding common stock as of 09/30/2025.

The firm has sole voting power over 1,835,017 shares and sole dispositive power over the full 2,886,232 shares, with no shared voting or dispositive power. Champlain certifies the position is held in the ordinary course of business and not for the purpose of influencing control of OneStream.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

OneStream, Inc.

(Name of Issuer)

Common Stock

(Title of Class of Securities)

68278B107

(CUSIP Number)

09/30/2025

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

SCHEDULE 13G

CUSIP No. 68278B107

1

Names of Reporting Persons

Champlain Investment Partners, LLC

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

VERMONT

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 1,835,017.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 2,886,232.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

2,886,232.00

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

3.3 %

12

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13G

Item 1.
(a)	Name of issuer: OneStream, Inc.
(b)	Address of issuer's principal executive offices: 191 N. CHESTER STREET, BIRMINGHAM, MICHIGAN, 48009
Item 2.
(a)	Name of person filing: Champlain Investment Partners, LLC
(b)	Address or principal business office or, if none, residence: 180 Battery St., Burlington, Vermont 05401
(c)	Citizenship: Vermont
(d)	Title of class of securities: Common Stock
(e)	CUSIP No.: 68278B107
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: 2886232
(b)	Percent of class: 3.3 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 1835017
	(ii) Shared power to vote or to direct the vote: 0
	(iii) Sole power to dispose or to direct the disposition of: 2886232
	(iv) Shared power to dispose or to direct the disposition of: 0
Item 5.	Ownership of 5 Percent or Less of a Class.
	Ownership of 5 percent or less of a class
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	Not Applicable
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	Not Applicable
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11. By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Champlain Investment Partners, LLC

Signature:	Matthew Garcia
Name/Title:	Chief Compliance Officer
Date:	02/12/2026

FAQ

What stake in OneStream, Inc. (OS) does Champlain Investment Partners report?

Champlain Investment Partners reports a beneficial ownership stake of 2,886,232 shares of OneStream, Inc. common stock. This position represents 3.3% of the company’s outstanding common stock as of 09/30/2025, according to the Schedule 13G filing.

Is Champlain Investment Partners’ OneStream (OS) stake considered passive or activist?

Champlain Investment Partners characterizes its OneStream stake as passive. It certifies the shares were acquired and are held in the ordinary course of business, not to change or influence control of OneStream or to participate in any control-related transactions.

How much voting power does Champlain Investment Partners have in OneStream (OS)?

Champlain Investment Partners has sole voting power over 1,835,017 shares of OneStream common stock. The filing states no shared voting power, meaning only this portion of the position can be voted directly at Champlain’s discretion.

What dispositive power does Champlain hold over its OneStream (OS) shares?

Champlain Investment Partners reports sole dispositive power over 2,886,232 shares of OneStream common stock. It discloses no shared dispositive power, indicating Champlain alone decides whether and when to sell or otherwise dispose of these shares.

Why did Champlain Investment Partners file a Schedule 13G for OneStream (OS)?

Champlain filed Schedule 13G because it beneficially owns more than 2,000,000 OneStream shares and 3.3% of the class. The firm certifies the holdings are in the ordinary course of business and not intended to influence control of the company.

Does Champlain Investment Partners own more than 5% of OneStream (OS) stock?

No. Champlain Investment Partners states its beneficial ownership is 3.3% of OneStream’s common stock, which is explicitly categorized as ownership of 5 percent or less of the class under Item 5 of the Schedule 13G.