# EDGAR Filing Document

**Accession Number:** 0001818383
**File Stem:** 0000950157-25-000649
**Filing Date:** 2025-8
**Character Count:** 13401
**Document Hash:** ec664f19f3c91a93ac08d5b029be22ee
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000950157-25-000649.hdr.sgml**: 20250808

**ACCESSION NUMBER**: 0000950157-25-000649

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

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20250808

**DATE AS OF CHANGE**: 20250808

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** MediaAlpha, Inc.
- **CENTRAL INDEX KEY:** 0001818383
- **STANDARD INDUSTRIAL CLASSIFICATION:** SERVICES-BUSINESS SERVICES, NEC [7389]
- **ORGANIZATION NAME:** 07 Trade & Services
- **EIN:** 851854133
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13D/A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-91822
- **FILM NUMBER:** 251198747

**BUSINESS ADDRESS:**
- **STREET 1:** 700 SOUTH FLOWER STREET
- **STREET 2:** SUITE 640
- **CITY:** LOS ANGELES
- **STATE:** CA
- **ZIP:** 90017
- **BUSINESS PHONE:** 619-393-9368

**MAIL ADDRESS:**
- **STREET 1:** 700 SOUTH FLOWER STREET
- **STREET 2:** SUITE 640
- **CITY:** LOS ANGELES
- **STATE:** CA
- **ZIP:** 90017
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** WHITE MOUNTAINS INSURANCE GROUP LTD
- **CENTRAL INDEX KEY:** 0000776867
- **STANDARD INDUSTRIAL CLASSIFICATION:** FIRE, MARINE & CASUALTY INSURANCE [6331]
- **ORGANIZATION NAME:** 02 Finance
- **EIN:** 942708455
- **STATE OF INCORPORATION:** D0
- **FISCAL YEAR END:** 1231

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

**BUSINESS ADDRESS:**
- **STREET 1:** 23 SOUTH MAIN STREET
- **STREET 2:** SUITE 3B
- **CITY:** HANOVER
- **STATE:** NH
- **ZIP:** 03755
- **BUSINESS PHONE:** 603 640 2200

**MAIL ADDRESS:**
- **STREET 1:** 23 SOUTH MAIN STREET
- **STREET 2:** SUITE 3B
- **CITY:** HANOVER
- **STATE:** NH
- **ZIP:** 03755

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** WHITE MOUNTAINS INSURANCE GROUP INC
- **DATE OF NAME CHANGE:** 19990603

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** FUND AMERICAN ENTERPRISES HOLDINGS INC
- **DATE OF NAME CHANGE:** 19920703

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** FUND AMERICAN COMPANIES INC
- **DATE OF NAME CHANGE:** 19920701

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

## SCHEDULE 13D

### Under the Securities Exchange Act of 1934

**(Amendment No. 5)**

**MediaAlpha, Inc.**

*(Name of Issuer)*

**Class A Common Stock, par value $0.01 per share**

*(Title of Class of Securities)*

**58450V104**

*(CUSIP Number)*

**Robert L. Seelig, Esq.**<br>23 South Main Street<br>Suite 3B<br>Hanover NH 03755<br>(603) 640-2200

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

**08/08/2025**

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

| **CUSIP No.** | **58450V104** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**White Mountains Insurance Group, Ltd.** | Name of reporting person<br>**White Mountains Insurance Group, Ltd.** | |
| 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>**AF** | Source of funds (See Instructions)<br>**AF** | |
| 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>**D0** | Citizenship or place of organization<br>**D0** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**900000.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**16956614.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**900000.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**16956614.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**17856614.00** | Aggregate amount beneficially owned by each reporting person<br>**17856614.00** | |
| 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>**31.7%** | Percent of class represented by amount in Row (11)<br>**31.7%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**HC** | Type of Reporting Person (See Instructions)<br>**HC** | |

---

| **CUSIP No.** | **58450V104** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**WM Hinson (Bermuda) Ltd.** | Name of reporting person<br>**WM Hinson (Bermuda) Ltd.** | |
| 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>**WC** | Source of funds (See Instructions)<br>**WC** | |
| 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>**D0** | Citizenship or place of organization<br>**D0** | |
| 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>**16956614.00** |
| 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>**16956614.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**16956614.00** | Aggregate amount beneficially owned by each reporting person<br>**16956614.00** | |
| 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>**30.1%** | Percent of class represented by amount in Row (11)<br>**30.1%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**CO** | Type of Reporting Person (See Instructions)<br>**CO** | |

---

**Item 1. Security and Issuer**

**(a) Title of Class of Securities:**
Class A Common Stock, par value $0.01 per share

**(b) Name of Issuer:**
MediaAlpha, Inc.

**(c) Address of Issuer's Principal Executive Offices:**
700 South Flower Street, Suite 640, Los Angeles, CA, 90017

This Amendment No. 5 (this "Amendment No. 5") to the Schedule 13D filed with the Securities and Exchange Commission (the "Commission") on June 30, 2023 (as amended and supplemented from time to time, this "Schedule 13D") is being filed jointly by White Mountains Insurance Group, Ltd. ("White Mountains") and WM Hinson (Bermuda) Ltd. ("WM Hinson" and, together with White Mountains, the "Reporting Persons") with respect to the Class A Common Stock, par value $0.01 per share (the "Class A Shares"), of MediaAlpha, Inc., a Delaware corporation (the "Issuer") beneficially owned by the Reporting Persons.

The purpose of this Amendment No. 5 is to report a change in the percentage of the Class A Shares beneficially owned by the Reporting Persons solely due to the change in the number of outstanding Class A Shares as disclosed in the Issuer's Form 10-Q filed with the Commission on August 6, 2025.

Except as set forth below, all Items of this Schedule 13D remain unchanged. Capitalized terms used in this Amendment No. 5 and not otherwise defined shall have the respective meanings assigned to such terms in this Schedule 13D.

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

**(a)**
Item 5(a)-(b) is amended and restated as follows:

The information set forth on the cover pages of this Amendment No. 5, and the information set forth or incorporated by reference in Items 2, 3, 4 and 6 of this Schedule 13D are hereby incorporated by reference in this Item 5(a)-(b).

As of the date hereof, White Mountains directly holds 900,000 Class A Shares of the Issuer and is the indirect beneficial owner of 16,956,614 Class A Shares directly held by its wholly owned direct subsidiary, WM Hinson, as presented herein. None of the Reporting Persons beneficially owns any shares of Class B Common Stock, par value $0.01 per share ("Class B Shares"). The Class A Shares held by the Reporting Persons represent approximately 31.68% of the outstanding Class A Shares.

As of the date hereof, and based on the knowledge of the Reporting Persons, the beneficial ownership of Class A Shares of the persons listed in Annex A is as follows: Steven Yi holds 2,030,232 Class A Shares and 46,166 Class B Shares, which results in Mr. Yi beneficially owning 2,174,158 Class A Shares, representing approximately 3.86% of the outstanding Class A Shares; Robert L. Seelig holds 9,000 Class A Shares, which results in Mr. Seelig beneficially owning 9,000 Class A Shares, representing approximately 0.02% of the outstanding Class A Shares; and John G. Sinkus holds 750 Class A Shares, which results in Mr. Sinkus beneficially owning 750 Class A Shares, representing less than 0.01% of the outstanding Class A Shares.

The beneficial ownership calculations set forth herein assume the exchange of any Class B Shares beneficially owned, together with a corresponding number of Class B-1 Units, for an equal number of Class A Shares pursuant to the Exchange Agreement. The percentage calculations set forth herein are based on 56,370,303 Class A Shares issued and outstanding as of July 31, 2025, as reported in the Issuer's Form 10-Q filed with the Commission on August 6, 2025, and are calculated in accordance with Rule 13d-3(d)(1)(i) under the Exchange Act.

In addition to the above, based solely on the information reported in the Schedule 13D filed by OBF Investments, LLC a Nevada limited liability company ("OBF"), and its Manager, Jason Heiling, on June 25, 2021, OBF holds 3,923,885 Class B Shares. OBF Investments is owned by trusts for the benefit of Mr. Yi and members of his family. Mr. Yi does not have any voting or dispositive control over the shares held by OBF. See the Schedule 13D filed by OBF and its Manager, Jason Heiling, on June 25, 2021, for additional information with respect to OBF.

By virtue of the relationships described under Item 2 of this Schedule 13D, White Mountains may be deemed, for purposes of Rule 13d-3 under the Exchange Act, to share the power to vote or dispose, or to direct the voting or disposition of the Class A Shares directly held by WM Hinson.

The filing of this Amendment No. 5 shall not be construed as an admission that any Reporting Person is the beneficial owner of any of the Class A Shares that such Reporting Person may be deemed to beneficially own. Without limiting the foregoing sentence, all of the Reporting Persons, other than with respect to Class A Shares directly held by such Reporting Person as described on each cover page to this Amendment No. 5, disclaim beneficial ownership of all Class A Shares reported in this Amendment No. 5. In addition, the filing of this Amendment No. 5 shall not be construed as an admission that any partner, member, director, officer or affiliate of any Reporting Person is the beneficial owner of any of the Class A Shares that such partner, member, director, officer or affiliate may be deemed to beneficially own.

In addition, because of the relationships among White Mountains and WM Hinson, on the one hand, and the other Stockholders' Agreement Parties, on the other hand, as a result of the Stockholders Agreement, the Reporting Persons may be deemed, pursuant to Rules 13d-3 and 13d-5 under the Act, to beneficially own the Class A Shares, Class B Shares or Class B-1 Units held in aggregate by the other Stockholders' Agreement Parties. Notwithstanding the foregoing, the filing of this Amendment No. 5 shall not be construed as an admission that any Reporting Person is the beneficial owner of any of the Class A Shares, Class B Shares or Class B-1 Units that such Reporting Person may be deemed to beneficially own. Further, each of the Reporting Persons disclaims membership in a group with each other Stockholders' Agreement Party.

**(b)**
Same as (a) above.

**(c)**
—

### 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:** White Mountains Insurance Group, Ltd.

**Signature:** /s/ Robert L. Seelig

**Name/Title:** Robert L. Seelig - Executive Vice President and General Counsel

**Date:** 08/08/2025

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:** WM Hinson (Bermuda) Ltd.

**Signature:** /s/ John G. Sinkus

**Name/Title:** John G. Sinkus - Vice President

**Date:** 08/08/2025