[Form 4] MAGNITE, INC. Insider Trading Activity

Rhea-AI Filing Summary

Magnite, Inc. (MGNI) reported an insider equity transaction by its Chief Accounting Officer on 11/15/2025. The filing shows a disposition of 3,549 shares of common stock at $14.15 per share, coded as transaction type "F," which indicates shares were withheld by the company to cover tax obligations. These shares were forfeited in connection with the vesting of restricted stock units under a non-discretionary, issuer-mandated arrangement. Following this tax withholding transaction, the reporting officer beneficially owns 89,349 shares of Magnite common stock directly.

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

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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^*

Gephart Brian

(Last) (First) (Middle)

C/O MAGNITE, INC.

1250 BROADWAY, 9TH FLOOR

(Street)

NEW YORK NY 10001

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
MAGNITE, INC. [ MGNI ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
11/15/2025

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

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

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

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
Common Stock	11/15/2025		F(1)		3,549	D	$14.15	89,349	D

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

Explanation of Responses:

1. Represents the non-discretionary forfeiture of shares on behalf of the Reporting Person pursuant to an arrangement mandated by the Issuer to cover the tax withholding obligations associated with the vesting of restricted stock units.

	/s/ Aaron Saltz, attorney-in-fact	11/18/2025
	** 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.

FAQ

What insider transaction did Magnite (MGNI) report in this Form 4?

The Form 4 reports that Magnite's Chief Accounting Officer disposed of 3,549 shares of common stock on 11/15/2025 in a transaction coded "F" at a price of $14.15 per share.

Why were 3,549 Magnite (MGNI) shares disposed of by the officer?

The 3,549 shares represent a non-discretionary forfeiture mandated by Magnite to cover tax withholding obligations arising from the vesting of restricted stock units held by the Chief Accounting Officer.

How many Magnite (MGNI) shares does the reporting officer own after this transaction?

After the reported tax withholding transaction, the officer beneficially owns 89,349 shares of Magnite common stock in direct ownership.

What does transaction code "F" mean in this Magnite (MGNI) Form 4?

Transaction code "F" indicates a disposition of shares to pay the exercise or tax withholding price, in this case a forfeiture of shares to satisfy tax obligations related to restricted stock unit vesting.

Is this Magnite (MGNI) Form 4 filed by one or multiple reporting persons?

The Form 4 is indicated as being filed by one reporting person, who serves as Magnite's Chief Accounting Officer.

Does this Form 4 involve any derivative securities of Magnite (MGNI)?

Table II for derivative securities is included but shows no specific derivative transactions reported in the excerpt; the detailed activity relates to non-derivative common stock used to cover tax withholding.