# EDGAR Filing Document

**Accession Number:** 0002027929
**File Stem:** 0002027929-26-000003
**Filing Date:** 2026-2
**Character Count:** 10028
**Document Hash:** 2e942f74d5bcafd3fda296bf7a327050
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0002027929-26-000003.hdr.sgml**: 20260213

**ACCESSION NUMBER**: 0002027929-26-000003

**CONFORMED SUBMISSION TYPE**: SCHEDULE 13G/A

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20260213

**DATE AS OF CHANGE**: 20260213

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** OneStream, Inc.
- **CENTRAL INDEX KEY:** 0001889956
- **STANDARD INDUSTRIAL CLASSIFICATION:** SERVICES-PREPACKAGED SOFTWARE [7372]
- **ORGANIZATION NAME:** 06 Technology
- **EIN:** 873199478
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13G/A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-94587
- **FILM NUMBER:** 26635113

**BUSINESS ADDRESS:**
- **STREET 1:** 191 N. CHESTER STREET
- **CITY:** BIRMINGHAM
- **STATE:** MI
- **ZIP:** 48009
- **BUSINESS PHONE:** (248) 650-1490

**MAIL ADDRESS:**
- **STREET 1:** 191 N. CHESTER STREET
- **CITY:** BIRMINGHAM
- **STATE:** MI
- **ZIP:** 48009
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Shea Thomas Anthony
- **CENTRAL INDEX KEY:** 0002027929

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13G/A

**MAIL ADDRESS:**
- **STREET 1:** C/O ONESTREAM, INC.
- **STREET 2:** 362 SOUTH STREET
- **CITY:** ROCHESTER
- **STATE:** MI
- **ZIP:** 48307

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## SCHEDULE 13G

### Under the Securities Exchange Act of 1934

**(Amendment No. 1)**

**Issuer:** ONESTREAM, INC.

**Title of Class of Securities:** Class A Common Stock, par value $0.0001 per share

**CUSIP Number:** 68278B107

**Date of Event Which Requires Filing of this Statement:** 12/31/2025

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

- [ ] Rule 13d-1(b)

- [ ] Rule 13d-1(c)

- [x] Rule 13d-1(d)

---

| 1. | Names of Reporting Persons<br>Thomas  Anthony Shea | Names of Reporting Persons<br>Thomas  Anthony Shea |
|:---|:---|:---|:---|
| 2. | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] | Check the Appropriate Box if a Member of a Group (See Instructions)<br>(a) [ ] (b) [x] |
| 3. | SEC Use Only | SEC Use Only |
| 4. | Citizenship or Place of Organization<br>X1 | Citizenship or Place of Organization<br>X1 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 5. | Sole Voting Power<br>5897454.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 6. | Shared Voting Power<br>12275805.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 7. | Sole Dispositive Power<br>5897454.00 |
| Number of<br>Shares<br>Beneficially<br>Owned by<br>Each<br>Reporting<br>Person<br>With | 8. | Shared Dispositive Power<br>12275805.00 |
| 9. | Aggregate Amount Beneficially Owned by Each Reporting Person<br>18173259.00 | Aggregate Amount Beneficially Owned by Each Reporting Person<br>18173259.00 |
| 10. | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] | Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions) [ ] |
| 11. | Percent of Class Represented by Amount in Row (9)<br>16.3% | Percent of Class Represented by Amount in Row (9)<br>16.3% |
| 12. | Type of Reporting Person (See Instructions)<br>IN | Type of Reporting Person (See Instructions)<br>IN |

**Comment for Type of Reporting Person:** Items 5, 7, and 9 consist of (i) 325,232 shares of Class D common stock, par value $0.0001 per share ("Class D Common Stock"), held by TSICU Corp., of which Mr. Shea is the sole owner and maintains control, issuable upon redemption or exchange of Common Units of OneStream Software LLC ("Common Units"), together with the cancellation of an equal number of shares of Class C common stock, par value $0.0001 per share ("Class C Common Stock"); (ii) 3,894,049 shares of Class D Common Stock held of record by Mr. Shea; (iii) 57,617 shares of Class A common stock, par value $0.0001 per share ("Class A Common Stock") held of record by Mr. Shea; and (iv) 1,620,556 shares of Class A Common Stock subject to options that are vested and exercisable within 60 days of December 31, 2025.

Items 6, 8, and 9 consist of (i) 7,525,803 shares of Class D Common Stock held by the Shea Family Trust dated December 25, 2019, of which Mr. Shea's spouse serves as co-trustee; and (ii) 4,750,002 shares of Class D Common Stock held by the Thomas A. Shea 2020 Annuity Trust dated December 23, 2020, of which Mr. Shea's spouse serves as trustee.

Items 5, 6, 7, 8, and 9 assume conversion of Class D Common Stock beneficially owned by Mr. Shea, including those shares issuable upon redemption or exchange of Common Units, into Class A Common Stock. Each share of Class D Common Stock is convertible at any time at the option of the holder into one share of Class A Common Stock. In addition, each share of Class D Common Stock will convert automatically 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 Mr. Shea 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.

Item 11 is based on the quotient obtained by dividing (a) the aggregate amount beneficially owned by Mr. Shea as set forth in Item 9 by (b) the sum of (i) 93,318,973 shares of Class A Common Stock outstanding as of December 31, 2025, as reported by the Issuer to the Reporting Person; (ii) 325,232 shares of Class D Common Stock issuable upon redemption or exchange of the Common Units; (iii) 16,169,854 shares of Class D Common Stock beneficially owned by Mr. Shea; and (iv) 1,620,556 shares of Class A Common Stock subject to options that are vested and exercisable within 60 days of December 31, 2025. The aggregate number of shares of Class D Common Stock beneficially owned by Mr. Shea, including those issuable upon redemption or exchange of Common Units, as set forth in clauses (ii) and (iii) of this footnote are treated as converted into Class A Common Stock only for the purpose of computing the percentage ownership of Mr. Shea.

---

**Item 1(a). Name of Issuer:**
ONESTREAM, INC.

**Item 1(b). Address of Issuer's Principal Executive Offices:**
191 N. Chester Street, Birmingham, MI, 48009.

**Item 2(a). Name of Person Filing:**
This statement is filed by Thomas Anthony Shea, also referred to herein as the "Reporting Person."

**Item 2(b). Address of Principal Business Office:**
c/o OneStream, Inc.

191 N. Chester Street

Birmingham, Michigan 48009

**Item 2(c). Citizenship:**
See response to Item 4 on the cover page.

**Item 2(d). Title of Class of Securities:**
Class A Common Stock, par value $0.0001 per share

**Item 2(e). CUSIP Number:**
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:**

See response to Item 9 on the cover page hereto.

**(b) Percent of class:**

See response to Item 11 on the cover page hereto

**(c) Number of shares as to which the person has:**

**(i) Sole power to vote or to direct the vote:**

See response to Item 5 on the cover page hereto.

**(ii) Shared power to vote or to direct the vote:**

See response to Item 6 on the cover page hereto.

**(iii) Sole power to dispose or to direct the disposition of:**

See response to Item 7 on the cover page hereto.

**(iv) Shared power to dispose or to direct the disposition of:**

See response to Item 8 on the cover page hereto.

**Item 5. Ownership of Five Percent or Less of a Class.**

[x] If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following.

**Item 6. Ownership of More than 5 Percent on Behalf of Another Person.**

Not Applicable

**Item 7. Identification and Classification of the Subsidiary**

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. Certification:**

—

### 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.

**Thomas  Anthony Shea**

**Date:** 02/13/2026

**By:** /s/ Thomas Anthony Shea

**Name & Title:** Thomas Anthony Shea