MediaAlpha owner WM Hinson sells 5.5M shares

The selling 10% owner directly held 11,456,223 MAX Class A shares afterward; White Mountains was deemed to beneficially own 12,356,223 shares.

Available on EDGAR 11/05/2026 - 09:04 PM EST Accepted by SEC EDGAR 11/05/2026 - 09:04 PM EST Learn about SEC filing dates

Rhea-AI Filing Summary

MediaAlpha, Inc. (MAX) 10% owner WM Hinson (Bermuda) Ltd., a wholly owned direct subsidiary of White Mountains Insurance Group, Ltd., sold 5,500,391 Class A common shares on November 4, 2026, at $13.90 per share. The shares were sold to J.P. Morgan Securities LLC pursuant to Rule 144. No Rule 10b5-1 plan is reported.

Insider Trade Summary

Net Seller: 5,500,391 shares

Net Sell 1 txn

Insider WHITE MOUNTAINS INSURANCE GROUP LTD, WM Hinson (Bermuda) Ltd.

Role 10% Owner | 10% Owner

Sold 5,500,391 shs ($76.46M)

Type	Security	Shares	Price	Value
Sale	Class A Common Stock F1, F2	5,500,391	$13.90	$76.46M

Holdings After Transaction: Class A Common Stock — 12,356,223 shares (Indirect, See Footnote)

Footnotes (2)

1. F1. On November 4, 2026, WM Hinson (Bermuda) Ltd., a wholly owned direct subsidiary of White Mountains Insurance Group, Ltd., sold 5,500,391 shares of Class A common stock of MediaAlpha, Inc. to J.P. Morgan Securities LLC pursuant to Rule 144 under the Securities Act of 1933, as amended, at a price of $13.90 per share.
2. F2. Includes 900,000 shares of Class A common stock owned directly by White Mountains Insurance Group, Ltd. and 11,456,223 shares of Class A common stock owned directly by WM Hinson (Bermuda) Ltd., following the reported transaction. White Mountains Insurance Group, Ltd. has indirect pecuniary interest in the securities held by WM Hinson (Bermuda) Ltd. Consequently, White Mountains Insurance Group, Ltd. is deemed to beneficially own the securities held directly by WM Hinson (Bermuda) Ltd. The board of directors and senior officers of White Mountains Insurance Group, Ltd. disclaim beneficial ownership with respect to such securities.

Key Figures

Class A common shares sold: 5,500,391 shares Sale price: $13.90 per share WM Hinson shares directly owned after sale: 11,456,223 shares +1 more

4 metrics

Class A common shares sold 5,500,391 shares Sold on November 4, 2026

Sale price $13.90 per share Sale on November 4, 2026

WM Hinson shares directly owned after sale 11,456,223 shares Class A common stock

White Mountains beneficial ownership after sale 12,356,223 shares Includes 900,000 shares owned directly by White Mountains and shares owned directly by WM Hinson

Key Terms

Rule 144, indirect pecuniary interest, beneficially own

3 terms

Rule 144 regulatory

"sold ... pursuant to Rule 144 under the Securities Act of 1933"

Rule 144 is a U.S. securities regulation that sets conditions under which restricted or insider-held shares can be legally resold to the public, such as required holding periods, availability of public information, limits on how much can be sold at once, and certain filing requirements. For investors it matters because it determines when previously locked-up shares can enter the market — like a release valve that can increase supply, affect share price, and signal insider intent.

indirect pecuniary interest financial

"has indirect pecuniary interest in the securities held by WM Hinson"

beneficially own regulatory

"deemed to beneficially own the securities held directly by WM Hinson"

Beneficially own means having the economic rights and risks of a security—such as the right to receive dividends, sell the shares, or profit from price changes—whether or not your name appears on the official share register. Think of it like renting a car: you use it and reap the benefits even if the title lists someone else. Investors care because beneficial ownership determines who truly controls value, must be disclosed under securities rules, and can signal potential influence or trading activity that affects a stock’s price.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

How many MAX shares did WM Hinson sell and at what price?

WM Hinson (Bermuda) Ltd. sold 5,500,391 MAX Class A common shares at $13.90 per share on November 4, 2026. The shares were sold to J.P. Morgan Securities LLC pursuant to Rule 144, and no Rule 10b5-1 plan is reported.

How many MAX shares did WM Hinson hold after the sale?

WM Hinson directly owned 11,456,223 Class A common shares after the sale. White Mountains Insurance Group, Ltd. was reported as beneficially owning 12,356,223 shares, including 900,000 it owned directly and shares owned directly by WM Hinson.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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SEC Form 4

FORM 4

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

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

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^*

WHITE MOUNTAINS INSURANCE GROUP LTD

(Last) (First) (Middle)

23 SOUTH MAIN STREET

SUITE 3B

(Street)

HANOVER NEW HAMPSHIRE 03755

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
MediaAlpha, Inc. [ MAX ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
11/04/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

	Form filed by One Reporting Person
X	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Class A Common Stock(1)	11/04/2026		S		5,500,391	D	$13.9	12,356,223	I	See Footnote(2)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

1. Name and Address of Reporting Person^*

WHITE MOUNTAINS INSURANCE GROUP LTD

(Last) (First) (Middle)

23 SOUTH MAIN STREET

SUITE 3B

(Street)

HANOVER NEW HAMPSHIRE 03755

(City) (State) (Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

WM Hinson (Bermuda) Ltd.

(Last) (First) (Middle)

26 REID STREET

SUITE 601

(Street)

HAMILTON HM 11

(City) (State) (Zip)

BERMUDA

(Country)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

Explanation of Responses:

1. On November 4, 2026, WM Hinson (Bermuda) Ltd., a wholly owned direct subsidiary of White Mountains Insurance Group, Ltd., sold 5,500,391 shares of Class A common stock of MediaAlpha, Inc. to J.P. Morgan Securities LLC pursuant to Rule 144 under the Securities Act of 1933, as amended, at a price of $13.90 per share.

2. Includes 900,000 shares of Class A common stock owned directly by White Mountains Insurance Group, Ltd. and 11,456,223 shares of Class A common stock owned directly by WM Hinson (Bermuda) Ltd., following the reported transaction. White Mountains Insurance Group, Ltd. has indirect pecuniary interest in the securities held by WM Hinson (Bermuda) Ltd. Consequently, White Mountains Insurance Group, Ltd. is deemed to beneficially own the securities held directly by WM Hinson (Bermuda) Ltd. The board of directors and senior officers of White Mountains Insurance Group, Ltd. disclaim beneficial ownership with respect to such securities.

Remarks:

Joint/Group Beneficial Owners: WM Hinson (Bermuda) Ltd. - (a wholly owned direct subsidiary of White Mountains Insurance Group, Ltd.)

	White Mountains Insurance Group, Ltd., by Robert L. Seelig, its EVP and General Counsel, /s/ Robert L. Seelig	11/05/2026
	WM Hinson (Bermuda) Ltd., by John G. Sinkus, its Vice President, /s/ John G. Sinkus	11/05/2026
	** Signature of Reporting Person	Date
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.
* Form 4: SEC 1474 (03-26)