# EDGAR Filing Document

**Accession Number:** 0000876883
**File Stem:** 0001437749-26-001214
**Filing Date:** 2026-1
**Character Count:** 19412
**Document Hash:** cbc38e92b73a323f349ef8cd904b0a04
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001437749-26-001214.hdr.sgml**: 20260113

**ACCESSION NUMBER**: 0001437749-26-001214

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

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20260113

**DATE AS OF CHANGE**: 20260113

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Stagwell Inc
- **CENTRAL INDEX KEY:** 0000876883
- **STANDARD INDUSTRIAL CLASSIFICATION:** SERVICES-ADVERTISING AGENCIES [7311]
- **ORGANIZATION NAME:** 07 Trade & Services
- **EIN:** 980364441
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13D/A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-53561
- **FILM NUMBER:** 26531201

**BUSINESS ADDRESS:**
- **STREET 1:** ONE WORLD TRADE CENTER, FLOOR 65
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10007
- **BUSINESS PHONE:** 646 429 1800

**MAIL ADDRESS:**
- **STREET 1:** ONE WORLD TRADE CENTER, FLOOR 65
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10007

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MDC Stagwell Holdings Inc
- **DATE OF NAME CHANGE:** 20210729

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MDC PARTNERS INC
- **DATE OF NAME CHANGE:** 20040206

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MDC CORP INC
- **DATE OF NAME CHANGE:** 20001204
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Stagwell Group LLC
- **CENTRAL INDEX KEY:** 0001771444

**ORGANIZATION NAME:**
- **EIN:** 472906614
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

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

**BUSINESS ADDRESS:**
- **STREET 1:** 1674 MERIDIAN AVENUE
- **STREET 2:** SUITE 210
- **CITY:** MIAMI BEACH
- **STATE:** FL
- **ZIP:** 33139
- **BUSINESS PHONE:** 202-478-4916

**MAIL ADDRESS:**
- **STREET 1:** 1674 MERIDIAN AVENUE
- **STREET 2:** SUITE 210
- **CITY:** MIAMI BEACH
- **STATE:** FL
- **ZIP:** 33139

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

## SCHEDULE 13D

### Under the Securities Exchange Act of 1934

**(Amendment No. 18)**

**Stagwell Inc**

*(Name of Issuer)*

**Class A Common Stock**

*(Title of Class of Securities)*

**85256A109**

*(CUSIP Number)*

**Mark J. Penn**<br>c/o The Stagwell Group LLC<br>1808 I Street, NW, 6th Floor<br>Washington DC 20006<br>(917) 765-2638

*(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)*

**12/15/2025**

*(Date of Event Which Requires Filing of this Statement)*

| **CUSIP No.** | **85256A109** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Stagwell Group LLC** | Name of reporting person<br>**Stagwell Group LLC** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**OO** | Source of funds (See Instructions)<br>**OO** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**2000000.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**2000000.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**0.00** | Aggregate amount beneficially owned by each reporting person<br>**0.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**0.8%** | Percent of class represented by amount in Row (11)<br>**0.8%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**OO** | Type of Reporting Person (See Instructions)<br>**OO** | |

---

| **CUSIP No.** | **85256A109** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Stagwell Agency Holdings LLC** | Name of reporting person<br>**Stagwell Agency Holdings LLC** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**OO** | Source of funds (See Instructions)<br>**OO** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**0.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**0.00** | Aggregate amount beneficially owned by each reporting person<br>**0.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**0.0%** | Percent of class represented by amount in Row (11)<br>**0.0%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**OO** | Type of Reporting Person (See Instructions)<br>**OO** | |

---

| **CUSIP No.** | **85256A109** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Penn Mark Jeffery** | Name of reporting person<br>**Penn Mark Jeffery** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**OO** | Source of funds (See Instructions)<br>**OO** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**X1** | Citizenship or place of organization<br>**X1** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**27368697.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**2000000.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**27368697.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**2000000.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**29368697.00** | Aggregate amount beneficially owned by each reporting person<br>**29368697.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**11.6%** | Percent of class represented by amount in Row (11)<br>**11.6%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**IN** | Type of Reporting Person (See Instructions)<br>**IN** | |

---

| **CUSIP No.** | **85256A109** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Stagwell Media LP** | Name of reporting person<br>**Stagwell Media LP** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[ ] (a)<br>[x] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**OO** | Source of funds (See Instructions)<br>**OO** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**X1** | Citizenship or place of organization<br>**X1** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**0.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**0.00** | Aggregate amount beneficially owned by each reporting person<br>**0.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**0.0%** | Percent of class represented by amount in Row (11)<br>**0.0%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**PN** | Type of Reporting Person (See Instructions)<br>**PN** | |

---

**Item 1. Security and Issuer**

**(a) Title of Class of Securities:**
Class A Common Stock

**(b) Name of Issuer:**
Stagwell Inc

**(c) Address of Issuer's Principal Executive Offices:**
ONE WORLD TRADE CENTER, FLOOR 65, NEW YORK, NY, 10007

This Amendment No. 18 to Schedule 13D (this "Amendment No. 18") is being filed jointly by: (i) Stagwell Agency Holdings LLC, a Delaware limited liability company, (ii) The Stagwell Group LLC, a Delaware limited liability company ("Stagwell Group"), (iii) Stagwell Media LP, a Delaware limited partnership ("Stagwell Media"), and (iv) Mark J. Penn, a United States citizen (collectively, the "Reporting Persons" and each, individually, a "Reporting Person"), and relates to the Class A common stock, par value $0.001 per share (the "Class A Common Stock"), of Stagwell Inc. (the "Issuer"). This Amendment No. 18 amends the original statement on Schedule 13D filed jointly by Stagwell Agency Holdings LLC, The Stagwell Group LLC, and Mark J. Penn with the Securities and Exchange Commission on March 25, 2019, as amended by Amendment No. 1 on June 26, 2020, Amendment No. 2 on October 4, 2020, Amendment No. 3 on December 22, 2020, Amendment No. 4 on June 7, 2021, Amendment No. 5 on June 14, 2021, Amendment No. 6 on June 17, 2021, Amendment No. 7 on July 9, 2021, Amendment No. 8 on July 16, 2021, Amendment No. 9 on August 4, 2021, Amendment No. 10 on October 7, 2021, Amendment No. 11 on February 7, 2022, Amendment No. 12 on March 14, 2023, Amendment No. 13 on May 19, 2023, Amendment No. 14 on April 2, 2025 ("Amendment No. 14"), Amendment No. 15 on April 8, 2025 ("Amendment No. 15"), Amendment No. 16 on April 18, 2025 ("Amendment No. 16"), and Amendment No. 17 on July 21, 2025 ("Amendment No. 17") (as so amended, the "Schedule 13D"), with respect to the Class A Common Stock.

This Amendment No. 18 amends the Schedule 13D as set forth herein. Unless otherwise indicated herein, each capitalized term used but not otherwise defined herein shall have the meaning given to such term in the Schedule 13D.

**Item 4. Purpose of Transaction**

Item 4 of the Schedule 13D is hereby amended and supplemented by adding the following:

On December 15, 2025, Mark J. Penn transferred 2,000,000 shares of Class A Common Stock to Stagwell Group in order to correct a distribution of shares by Stagwell Group to Mark J. Penn on July 17, 2025.

**Item 5. Interest in Securities of the Issuer**

**(a)**
Subparts (a) and (b) of Item 5 of the Schedule 13D are hereby amended and restated as follows:

Calculations of the percentage of shares of Class A Common Stock beneficially owned assume a total of 252,118,245 issued and outstanding shares of Class A Common Stock as of December 15, 2025.

The aggregate number and percentage of shares of Class A Common Stock beneficially owned by each Reporting Person and, for each Reporting Person, the number of shares of Class A Common Stock as to which there is sole power to vote or to direct the vote, shared power to vote or to direct the vote, sole power to dispose or to direct the disposition, or shared power to dispose or to direct the disposition are set forth on rows 7 through 11 and row 13 of the cover pages of this Amendment No. 18 and are incorporated herein by reference.

As of the date hereof, Mark J. Penn directly holds 27,368,697 shares of Class A Common Stock, of which 640,988 are unvested shares of restricted stock that are not scheduled to vest until March 1, 2026, subject to achievement of financial performance targets and continued employment. 1,750,000 shares previously held by Mark J. Penn were transferred as a gift, as described on Mr. Penn's Form 4, dated August 5, 2025. In addition, as of the date hereof, Mr. Penn directly holds (i) 191,733 restricted stock units that are not scheduled to vest until March 7, 2026, subject to continued employment (ii) 1,500,000 SARs granted on December 14, 2021 with a base price of $8.27 per share, all of which are vested and exercisable as of the date hereof and (iii) 225,000 SARs granted on March 1, 2023 with a base price of $6.79 per share, of which 150,000 are vested and exercisable as of the date hereof and 75,000 vest on March 1, 2026.

Stagwell Group is the general partner and manager of Stagwell Media and is the manager of Stagwell Agency Holdings LLC, which is a subsidiary of Stagwell Media. Mark J. Penn is the controlling person of Stagwell Group. Mark J. Penn is the controlling person of Stagwell Media.

To the best knowledge of the Reporting Persons, none of the individuals named in Item 2 beneficially owns any shares of Class A Common Stock except as described herein.

**(b)**
Subparts (a) and (b) of Item 5 of the Schedule 13D are hereby amended and restated as follows:

Calculations of the percentage of shares of Class A Common Stock beneficially owned assume a total of 252,118,245 issued and outstanding shares of Class A Common Stock as of December 15, 2025.

The aggregate number and percentage of shares of Class A Common Stock beneficially owned by each Reporting Person and, for each Reporting Person, the number of shares of Class A Common Stock as to which there is sole power to vote or to direct the vote, shared power to vote or to direct the vote, sole power to dispose or to direct the disposition, or shared power to dispose or to direct the disposition are set forth on rows 7 through 11 and row 13 of the cover pages of this Amendment No. 18 and are incorporated herein by reference.

As of the date hereof, Mark J. Penn directly holds 27,368,697 shares of Class A Common Stock, of which 640,988 are unvested shares of restricted stock that are not scheduled to vest until March 1, 2026, subject to achievement of financial performance targets and continued employment. 1,750,000 shares previously held by Mark J. Penn were transferred as a gift, as described on Mr. Penn's Form 4, dated August 5, 2025. In addition, as of the date hereof, Mr. Penn directly holds (i) 191,733 restricted stock units that are not scheduled to vest until March 7, 2026, subject to continued employment (ii) 1,500,000 SARs granted on December 14, 2021 with a base price of $8.27 per share, all of which are vested and exercisable as of the date hereof and (iii) 225,000 SARs granted on March 1, 2023 with a base price of $6.79 per share, of which 150,000 are vested and exercisable as of the date hereof and 75,000 vest on March 1, 2026.

Stagwell Group is the general partner and manager of Stagwell Media and is the manager of Stagwell Agency Holdings LLC, which is a subsidiary of Stagwell Media. Mark J. Penn is the controlling person of Stagwell Group. Mark J. Penn is the controlling person of Stagwell Media.

To the best knowledge of the Reporting Persons, none of the individuals named in Item 2 beneficially owns any shares of Class A Common Stock except as described herein.

**(c)**
Subpart (c) of Item 5 of the Schedule 13D is hereby amended and restated as follows:

No transactions in shares of Class A Common Stock were effected by any Reporting Person during the sixty days before the date hereof, except as set forth in this Amendment No. 18.

Neither the filing of this Amendment No. 18 nor any of its contents shall be deemed to constitute an admission that any of the Reporting Persons is the beneficial owner of any securities covered by this statement for purposes of Section 13(d) of the Exchange Act, or for any other purpose, except to the extent of its or his pecuniary interest therein, if any, and such beneficial ownership is expressly disclaimed. The filing of this statement should not be construed to be an admission that any Reporting Person is a member of a "group" for the purposes of Sections 13(d) or 13(g) of the Exchange Act.

**Item 6. Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer.**

The disclosure set forth under Item 4 of this Amendment No. 18 is incorporated herein by reference.

### 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.

**Reporting Person:** Stagwell Group LLC

**Signature:** /s/ Mark J. Penn

**Name/Title:** Mark J. Penn/Manager

**Date:** 01/13/2026

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.

**Reporting Person:** Stagwell Agency Holdings LLC

**Signature:** /s/ Mark J. Penn

**Name/Title:** Mark J. Penn/Manager

**Date:** 01/13/2026

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.

**Reporting Person:** Penn Mark Jeffery

**Signature:** /s/ Mark J. Penn

**Name/Title:** Mark J. Penn

**Date:** 01/13/2026

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.

**Reporting Person:** Stagwell Media LP

**Signature:** /s/ Mark J. Penn

**Name/Title:** Mark J. Penn/Manager

**Date:** 01/13/2026