MGNI Form 4: Officer Katie Seitz Evans sold 8,345 shares under 10b5-1 plan

Rhea-AI Filing Summary

Magnite, Inc. (MGNI) insider sale disclosed on Form 4. The reporting person, Katie Seitz Evans (President, Operations), sold 8,345 shares of common stock on 08/25/2025 at $26 per share under a Rule 10b5-1 trading plan that was adopted on March 6, 2025. After the sale she beneficially owned 415,598 shares, reported as direct ownership. The Form 4 was signed by attorney-in-fact Aaron Saltz on 08/26/2025. The filing documents a planned disposition under an established trading plan rather than an ad hoc transaction.

Positive

• Transaction disclosed under a Rule 10b5-1 trading plan, indicating pre-specified trading intent (plan adopted March 6, 2025).
• Timely Form 4 filing signed by attorney-in-fact on 08/26/2025, one day after the transaction.

Negative

• Insider sale of 8,345 shares on 08/25/2025 which reduces direct holdings to 415,598 shares.
• No additional company financial context in this filing to assess broader impact on company fundamentals.

Insights

Securities Analyst

TL;DR: Insider sold shares via a 10b5-1 plan; transaction appears routine and disclosed promptly.

The reporting shows a discrete sale of 8,345 shares at $26 under a Rule 10b5-1 plan adopted March 6, 2025. The seller retains substantial direct holdings (415,598 shares) after the transaction. For investors, the key takeaway is transparency: the sale was executed pursuant to an established trading plan and the Form 4 was filed the following day by an attorney-in-fact. There is no additional company-level financial information in this filing to indicate broader operational impact.

Corporate Governance Expert

TL;DR: Governance practice observed: planned insider sale disclosed; no red flags in the filing itself.

The Form 4 clearly identifies the reporting persons role (President, Operations), the 10b5-1 plan adoption date, sale quantity, price and remaining beneficial ownership. The presence of a 10b5-1 plan and a prompt filing reduce concerns about opportunistic trading. The document does not report any amendments or other governance events. Based solely on this filing, the disclosure meets Section 16 transparency expectations.

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).

X

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)
08/25/2025

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	08/25/2025		S(1)		8,345	D	$26	415,598	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 pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 6, 2025.

	/s/ Aaron Saltz, attorney-in-fact	08/26/2025
	** 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 transaction did Katie Seitz Evans report on Form 4 for MGNI?

She sold 8,345 shares of Magnite common stock on 08/25/2025 at $26 per share.

Was the sale executed under a 10b5-1 trading plan for MGNI insider filings?

Yes. The sale was made pursuant to a Rule 10b5-1 trading plan adopted on March 6, 2025.

How many MGNI shares does the reporting person own after the transaction?

415,598 shares of common stock reported as beneficially owned following the sale.

When was the Form 4 signed and by whom?

Signed by Aaron Saltz, attorney-in-fact, on 08/26/2025.

What is the reporting persons role at Magnite in this Form 4?

President, Operations is listed as the reporting persons title.