Magnite Form 4: President Evans offloads 20k shares, keeps 443k stake

Rhea-AI Filing Summary

Magnite, Inc. (MGNI) filed a Form 4 disclosing transactions by President of Operations Katie Seitz Evans. On 06/16/2025 she exercised 20,000 stock options at an exercise price of $3.61 per share, immediately followed by a sale of the same 20,000 common shares at $18.50 per share. The exercise originated from an option grant dated 02/26/2018 that fully vested by February 2022.

Following the transactions, Evans’ direct common-stock holdings decreased by 20,000 shares to 442,788. She continues to hold 16,137 vested options with a $3.61 strike price expiring 02/26/2028.

The filing notes that both the exercise and sale were conducted under a Rule 10b5-1 trading plan adopted on 03/06/2025, providing advance notice and reducing interpretative risk around timing. No other derivatives or indirect holdings were reported.

Financial magnitude: gross sale proceeds approximate $370,000 versus an exercise cost of about $72,200, implying a before-tax gain of roughly $298,000. Despite the sale, Evans maintains a sizeable equity stake, representing continued alignment with shareholder interests.

Positive

• Executive retains 442,788 shares, maintaining significant equity alignment with shareholders.
• Transactions executed under a Rule 10b5-1 plan, demonstrating strong governance and reduced insider-timing risk.

Negative

• Sale of 20,000 shares at $18.50 represents insider monetisation of roughly $370k, which some investors may perceive as a mildly negative signal.

Insights

Securities Analyst

TL;DR – 20k-share insider sale via 10b5-1; holdings remain large, signalling limited directional insight.

The transaction is a routine option exercise and share sale, common for executives managing liquidity and taxes. Proceeds of ~$370k are modest relative to Magnite’s daily trading volume and Evans’ residual 443k-share position. Because the sale was pre-scheduled under a Rule 10b5-1 plan adopted three months prior, it reduces the informational value for timing the stock. Overall impact on valuation or sentiment should be minimal.

Corporate Governance Expert

TL;DR – Pre-planned trade aligns with governance best practices; no red flags detected.

The 10b5-1 plan indicates proactive compliance, and full disclosure of option vesting terms meets transparency standards. Evans’ remaining 16,137 options and 442,788 shares demonstrate continued ownership alignment. The exercise price far below market suggests historical compensation value but does not, by itself, raise governance concerns. Therefore, the filing is operationally routine and not materially impactful.

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)
06/16/2025

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	06/16/2025		M(1)		20,000	A	$3.61	462,788	D
Common Stock	06/16/2025		S(1)		20,000	D	$18.5	442,788	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
Stock Option (Right to Buy)	$3.61	06/16/2025		M(1)			20,000	(2)	02/26/2028	Common Stock	20,000	$0(3)	16,137	D

Explanation of Responses:

1. This exercise and subsequent sales were made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 6, 2025.

2. 25% of the total number of shares underlying this option vested on February 14, 2019 and the remaining shares vested 1/36 per month over the next 36 months thereafter.

3. Granted as compensation for services.

	/s/ Aaron Saltz, attorney-in-fact	06/18/2025
	** 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

How many Magnite (MGNI) shares did Katie Seitz Evans sell?

She sold 20,000 common shares on 06/16/2025 at $18.50 each.

What was the exercise price of the options used in the Form 4 filing?

The options were exercised at $3.61 per share.

Does Evans still hold Magnite shares after the sale?

Yes, she continues to hold 442,788 shares directly plus 16,137 vested options.

Was the transaction executed under a 10b5-1 trading plan?

Yes. The filing states the plan was adopted on 03/06/2025.

What is the total value of shares sold according to the Form 4?

Gross proceeds are approximately $370,000 (20,000 shares × $18.50).