Kayne Anderson Rudnick boosts stake in OneStream Inc (OS) to 5.4%

Rhea-AI Filing Summary

Kayne Anderson Rudnick Investment Management, LLC filed an amended Schedule 13G reporting passive ownership of OneStream Inc Class A shares. It reports beneficial ownership of 4,867,687 Onestream Ord Shs Class A, representing 5.4% of the class as of 12/31/2025.

The firm has sole voting power over 1,850,809 shares and shared voting power over 2,924,070 shares. It also has sole dispositive power over 1,943,617 shares and shared dispositive power over 2,924,070 shares, and certifies the stake is held in the ordinary course without intent to influence control.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 3)

OneStream Inc

(Name of Issuer)

Onestream Ord Shs Class A

(Title of Class of Securities)

68278B107

(CUSIP Number)

12/31/2025

(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

Kayne Anderson Rudnick Investment Management, 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

CALIFORNIA

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 1,850,809.00
6	Shared Voting Power 2,924,070.00
7	Sole Dispositive Power 1,943,617.00
8	Shared Dispositive Power 2,924,070.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

4,867,687.00

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)

5.4 %

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 St., Birmingham, MI, 48009, US
Item 2.
(a)	Name of person filing: Kayne Anderson Rudnick Investment Management, LLC
(b)	Address or principal business office or, if none, residence: 2000 Avenue of the Stars, Suite 1110, Los Angeles, 90067, CA, United States
(c)	Citizenship: CALIFORNIA
(d)	Title of class of securities: Onestream Ord Shs Class A
(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: 4,867,687
(b)	Percent of class: 5.4 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 1,850,809
	(ii) Shared power to vote or to direct the vote: 2,924,070
	(iii) Sole power to dispose or to direct the disposition of: 1,943,617
	(iv) Shared power to dispose or to direct the disposition of: 2,924,070
Item 5.	Ownership of 5 Percent or Less of a Class.
	Not Applicable
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.

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.

Kayne Anderson Rudnick Investment Management, LLC

Signature:	/s/Michael Shoemaker
Name/Title:	Chief Compliance Officer
Date:	02/13/2026

FAQ

What percentage of OneStream Inc (OS) does Kayne Anderson Rudnick report owning?

Kayne Anderson Rudnick reports beneficial ownership of 5.4% of OneStream Inc’s Class A shares. This corresponds to 4,867,687 Onestream Ord Shs Class A as of December 31, 2025, making it a significant institutional holder above the 5% reporting threshold.

How many OneStream Inc (OS) shares does Kayne Anderson Rudnick beneficially own?

Kayne Anderson Rudnick beneficially owns 4,867,687 Onestream Ord Shs Class A. This total includes shares over which it has varying voting and dispositive powers and represents 5.4% of the class as disclosed for the event date December 31, 2025.

What voting power does Kayne Anderson Rudnick have over its OneStream Inc (OS) shares?

Kayne Anderson Rudnick has sole voting power over 1,850,809 shares and shared voting power over 2,924,070 shares of OneStream Inc Class A stock. These figures define how many shares it can vote independently versus together with other parties.

What dispositive power does Kayne Anderson Rudnick hold over OneStream Inc (OS) shares?

Kayne Anderson Rudnick has sole dispositive power over 1,943,617 shares and shared dispositive power over 2,924,070 shares of OneStream Inc Class A. Dispositive power refers to its authority to sell or otherwise direct the disposition of these shares.

Is Kayne Anderson Rudnick seeking to influence control of OneStream Inc (OS)?

Kayne Anderson Rudnick certifies that its OneStream Inc shares were acquired and are held in the ordinary course of business. It states they were not acquired and are not held for the purpose or effect of changing or influencing control of the issuer.

What is the event date for Kayne Anderson Rudnick’s reported OneStream Inc (OS) holdings?

The reported ownership figures for Kayne Anderson Rudnick’s OneStream Inc Class A shares are as of December 31, 2025. This date is identified as the Date of Event Which Requires Filing for the amended Schedule 13G disclosure.