[Form 4] Magnite, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Katie Seitz Evans, President, Operations at Magnite, Inc. (MGNI), reported a non-discretionary sale of company stock on 08/18/2025. She disposed of 10,487 shares of common stock at $23.85 per share as part of a "sell to cover" to satisfy tax withholding obligations from the settlement of vested restricted stock units. After the transaction she beneficially owned 423,943 shares.

The filing notes the sale was mandated by the issuer's election to require withholding via sale and was not a discretionary trade by the reporting person. The Form 4 was signed on behalf of the reporting person by an attorney-in-fact.

Positive

• Transaction was disclosed as non-discretionary, clarifying it was a mandated sell-to-cover rather than a voluntary sale
• Filing specifies exact amounts: 10,487 shares sold at $23.85 and 423,943 shares beneficially owned after the sale

Negative

• None.

Insights

Securities Analyst

TL;DR: Routine, non-discretionary sell-to-cover of vested RSUs; small proportionate reduction in insider holdings.

The reported transaction is explicitly described as a mandated sale to satisfy tax withholding from vested restricted stock units. The sale amount—10,487 shares at $23.85—reduces the reporting person’s beneficial holdings to 423,943 shares. This is a common liquidity mechanism following vesting and, based solely on the disclosed facts, does not indicate voluntary cashing out of a substantial portion of holdings or a change in ownership intent.

Corporate Governance Expert

TL;DR: Governance practice consistent with standard issuer-mandated tax withholding; disclosure is clear and specific.

The Form 4 clarifies that the issuer elected to satisfy tax obligations by requiring sell-to-cover transactions, and the reporting person’s sale was executed under that policy. The filing shows transparency about the nature of the trade and quantifies post-transaction beneficial ownership. No other transactions or derivative activity are reported in this filing.

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
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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^*

Evans Katie Seitz

(Last) (First) (Middle)

C/O MAGNITE, INC.

1250 BROADWAY, 15TH 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)
	President, Operations

3. Date of Earliest Transaction (Month/Day/Year)
08/18/2025

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	08/18/2025		S(1)		10,487	D	$23.85	423,943	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. These shares were sold to cover the Reporting Person's tax obligation resulting from the settlement of vested Restricted Stock Units. The sale is mandated by the Issuer's election to require the satisfaction of tax withholding obligations to be funded by sell to cover transactions and does not represent a discretionary transaction by the Reporting Person.

	/s/ Aaron Saltz, attorney-in-fact	08/20/2025
	** 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 did the Form 4 for MGNI filed by Katie Seitz Evans report?

The Form 4 reports a sale of 10,487 shares of Magnite common stock on 08/18/2025 at $23.85 per share to satisfy tax withholding from vested RSUs.

Why were the shares sold by the reporting person in the MGNI Form 4?

The shares were sold as a sell-to-cover transaction mandated by the issuer to satisfy tax withholding obligations resulting from vesting of restricted stock units.

How many MGNI shares does Katie Seitz Evans beneficially own after the reported transaction?

After the reported sale, the filing shows she beneficially owns 423,943 shares.

Was the sale by the reporting person a discretionary transaction according to the filing?

No. The filing states the sale was mandated by the issuer's election and did not represent a discretionary transaction by the reporting person.

Does the Form 4 report any derivative transactions for Katie Seitz Evans?

No. The filing includes only a non-derivative sale of common stock and does not report any derivative securities activity.