# EDGAR Filing Document

**Accession Number:** 0002027929
**File Stem:** 0002027929-26-000011
**Filing Date:** 2026-4
**Character Count:** 12429
**Document Hash:** 10d7aba227b0f6b4e589f5284f6d88df
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0002027929-26-000011.hdr.sgml**: 20260403

**ACCESSION NUMBER**: 0002027929-26-000011

**CONFORMED SUBMISSION TYPE**: 4/A

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20260401

**FILED AS OF DATE**: 20260403

**DATE AS OF CHANGE**: 20260403

**REPORTING-OWNER**: 

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

**ORGANIZATION NAME:**

**FILING VALUES:**
- **FORM TYPE:** 4/A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-42187
- **FILM NUMBER:** 26839351

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

**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

**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

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

## FORM 4/A

### STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

[x] 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 for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

---

| | | |
|:---|:---|:---|
| **1. Name and Address of Reporting Person**<sup>*</sup><br>Shea Thomas Anthony<br><sub>(Last) (First) (Middle)</sub><br>C/O ONESTREAM, INC.<br>191 N. CHESTER STREET<br><sub>(Street)</sub><br>BIRMINGHAM, MI 48009<br><sub>(City) (State) (Zip)</sub> | **3. Date of Earliest Transaction (Month/Day/Year)**<br>2026-04-01 | **5. Relationship of Reporting Person(s) to Issuer**<br>(Check all applicable)<br>[X] Director [X] 10% Owner<br>[X] Officer (give title below) [ ] Other (specify below)<br>_CEO_ |
| **2. Issuer Name and Ticker or Trading Symbol**<br>OneStream, Inc. [ OS ] | **4. If Amendment, Date of Original Filed (Month/Day/Year)**<br>  | **6. Individual or Joint/Group Filing (Check Applicable Line)**<br>[X] Form filed by One Reporting Person<br>[ ] Form filed by More than One Reporting Person |

---

## Table I - Non-Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | 3. Transaction Code (V) | 3. Transaction Code (V) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 4. Securities Acquired (A) or Disposed of (D) | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| 1. Title of Security | 2. Transaction Date | 2A. Deemed Execution Date | Code | V | Amount | (A) or (D) | Price | 5. Amount of Securities Beneficially Owned | 6. Ownership Form | 7. Nature of Indirect Beneficial Ownership |
| Class A Common Stock | 2026-04-01 |  | D<sup>(1)</sup> |  | 80023 | D | <sup>(2)</sup> | 0 | D |  |
| Class A Common Stock | 2026-04-01 |  | D<sup>(1)</sup> |  | 379963 | D | <sup>(3)</sup> | 0 | D |  |

---

## Table II - Derivative Securities

---

|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | 4. Transaction Code (V) | 4. Transaction Code (V) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 5. Number of Derivative Securities Acquired (A) or Disposed of (D) | 6. Date Exercisable and Expiration Date | 6. Date Exercisable and Expiration Date | 7. Title and Amount of Underlying Securities | 7. Title and Amount of Underlying Securities | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| 1. Title of Derivative Security | 2. Conversion or Exercise Price | 3. Transaction Date | 3A. Deemed Execution Date | Code | V | (A) | (D) | Date Exercisable | Expiration Date | Title | Amount or Number of Shares | 8. Price of Derivative Security | 9. Number of Derivative Securities Beneficially Owned | 10. Ownership Form | 11. Nature of Indirect Beneficial Ownership |
| Common Units | <sup>(4)</sup> | 2026-04-01 |  | D<sup>(1)</sup> |  |  | 325232 | <sup>(4)</sup> | <sup>(4)</sup> | Class D Common Stock | 325232 | <sup>(4)</sup> | 0 | I | See footnote<sup>(5)</sup> |
| Class D Common Stock | <sup>(6)</sup> | 2026-04-01 |  | D<sup>(1)</sup> |  |  | 4313836 | <sup>(6)</sup> | <sup>(6)</sup> | Class A Common Stock | 4313836 | <sup>(6)</sup> | 0 | D |  |
| Class D Common Stock | <sup>(6)</sup> | 2026-04-01 |  | D<sup>(1)</sup> |  |  | 2814351 | <sup>(6)</sup> | <sup>(6)</sup> | Class A Common Stock | 2814351 | <sup>(6)</sup> | 0 | I | See footnote<sup>(7)</sup> |
| Class D Common Stock | <sup>(8)</sup> | 2026-04-01 |  | D<sup>(1)</sup> |  |  | 9041667 | <sup>(8)</sup> | <sup>(8)</sup> | Class A Common Stock | 9041667 | <sup>(8)</sup> | 0 | I | See footnote<sup>(7)</sup> |
| Stock Option (right to buy) | $10.65 | 2026-04-01 |  | D<sup>(1)</sup> |  |  | 619835 | <sup>(9)</sup> | 2031-12-04 | Class A Common Stock | 619835 | <sup>(9)</sup> | 0 | D |  |
| Stock Option (right to buy) | $10.65 | 2026-04-01 |  | D<sup>(1)</sup> |  |  | 504472 | <sup>(9)</sup> | 2033-03-05 | Class A Common Stock | 504472 | <sup>(9)</sup> | 0 | D |  |
| Stock Option (right to buy) | $10.65 | 2026-04-01 |  | D<sup>(1)</sup> |  |  | 149979 | <sup>(10)</sup> | 2033-03-05 | Class A Common Stock | 149979 | <sup>(10)</sup> | 0 | D |  |
| Stock Option (right to buy) | $14.51 | 2026-04-01 |  | D<sup>(1)</sup> |  |  | 473008 | <sup>(9)</sup> | 2034-03-10 | Class A Common Stock | 473008 | <sup>(9)</sup> | 0 | D |  |
| Stock Option (right to buy) | $14.51 | 2026-04-01 |  | D<sup>(1)</sup> |  |  | 435161 | <sup>(10)</sup> | 2034-03-10 | Class A Common Stock | 435161 | <sup>(10)</sup> | 0 | D |  |
| Stock Option (right to buy) | $20 | 2026-04-01 |  | D<sup>(1)</sup> |  |  | 55795 | <sup>(9)</sup> | 2034-07-22 | Class A Common Stock | 55795 | <sup>(9)</sup> | 0 | D |  |
| Stock Option (right to buy) | $20 | 2026-04-01 |  | D<sup>(1)</sup> |  |  | 92992 | <sup>(10)</sup> | 2034-07-22 | Class A Common Stock | 92992 | <sup>(10)</sup> | 0 | D |  |

---

### Footnotes:

(1) Pursuant to the Agreement and Plan of Merger (the "Merger Agreement"), dated January 6, 2026, by and among OneStream, Inc. ("Issuer"), OneStream Software LLC, a subsidiary of Issuer ("Company LLC"), Onward AcquireCo Inc. ("Parent"), Onward Merger Sub 2, LLC ( "Merger Sub I") and Onward Merger Sub, Inc. ("Merger Sub II"), on April 1, 2026, Merger Sub 1 merged with and into Company LLC (the "First Merger"), with Company LLC surviving the First Merger and becoming a subsidiary of Parent, and Merger Sub II merged with and into Issuer (the "Second Merger" and together with the First Merger, the "Mergers"), with Issuer surviving the Second Merger and becoming a subsidiary of Parent.

(2) Pursuant to the Merger Agreement, at the effective time of the Mergers (the "Effective Time"), each share of Issuer Class A Common Stock was cancelled and converted into the right to receive $24.00 per share in cash (the "Per Share Price") without interest, less applicable withholding taxes.

(3) Represents an equal number of restricted stock units ("RSUs"). At the Effective Time, each unvested RSU award was cancelled and converted into the contingent right to receive a cash award, without interest, equal to the product of (a) the Per Share Price multiplied by (b) the total number of shares of Issuer's Class A Common Stock covered by such RSU award, less applicable withholding taxes. The vesting terms and conditions applicable to the unvested RSU awards as of immediately prior to the Mergers will remain in effect following the Mergers, provided that the vesting and payment of these cash awards to the extent not yet paid will accelerate and be paid upon the earlier of March 15, 2027 or a termination or resignation of the Reporting Person's employment with the Issuer, as a privately held entity, following the Mergers for any reason other than for cause.

(4) At the Effective Time, each Common Unit was cancelled and converted into the right to receive an amount in cash, without interest, equal to the Per Share Price, less applicable withholding taxes.  Each corresponding share of Class C Common Stock was cancelled and converted into the right to receive $0.0001 in cash, without interest, less applicable withholding taxes.

(5) Shares held of record by the TSICU Corp. TSICU Corp. is a subchapter S corporation controlled by the Reporting Person, who has sole voting and dispositive power over the shares held by it.

(6) Pursuant to the Merger Agreement, at the Effective Time, each share of Class D Common Stock was cancelled and converted into the right to receive the Per Share Price, without interest, less applicable withholding taxes.

(7) Shares held of record by the Shea Family Trust dated December 25, 2019 (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.

(8) At the Effective Time, the shares of Class D Common Stock were reinvested into Issuer, as a privately held entity following the Mergers, and were exchanged for equity interests in an entity that controls Parent.

(9) At the Effective Time, each vested option was cancelled and converted into the right to receive an amount in cash, without interest, equal to the product of (a) the total number of shares of Class A Common Stock subject to the option multiplied by (b) the excess, if any, of the Per Share Price over the exercise price per share of the option, less applicable withholding taxes.

(10) At the Effective Time, each unvested option was cancelled and converted into the contingent right to receive a cash award, without interest, equal to the product of (a) the total number of shares of Class A Common Stock subject to the option multiplied by (b) the excess, if any, of the Per Share Price over the exercise price per share of such option, less applicable withholding taxes.  The vesting terms and conditions applicable to the unvested option as of immediately prior to the Mergers will remain in effect following the Mergers, provided that the vesting and payment of these cash awards to the extent not yet paid will accelerate and be paid upon the earlier of March 15, 2027 or a termination or resignation of the Reporting Person's employment with the Issuer, as a privately held entity, following the Mergers for any reason other than for cause.

**Remarks:**
This amendment to the Reporting Person's Form 4 filed on April 2, 2026 is being filed solely to update footnotes 3 and 10 to clarify the vesting and payment terms following the Mergers of the cash awards applicable to the unvested RSU and stock option awards held by the Reporting Persons.

**Signature:** /s/ Holly Koczot, attorney-in-fact  
**Date:** 2026-04-03

### Remarks:

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* 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).

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.

**Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.**