Magnite Insider Filing: CFO Converts Options, Nets $0.7M in Share Sale

Rhea-AI Filing Summary

Magnite, Inc. (MGNI) – Form 4 insider activity

Chief Financial Officer David Day reported a same-day option exercise and share sale executed on 18 June 2025 under a pre-arranged Rule 10b5-1 trading plan adopted 13 March 2025.

• Option exercise: 38,146 employee stock options exercised at an exercise price of $4.92
• Share sale: The exact 38,146 shares were disposed of on the open market at an average price of $18.95.
• Gross transaction value: Approximately $723k in proceeds (38,146 × $18.95) versus a cash outlay of roughly $188k for the exercise, implying a pre-tax gain of about $535k.
• Post-transaction ownership: Day retains 443,528 Magnite common shares held directly, indicating continued exposure to the company’s equity despite the sale.

There were no derivative holdings remaining from the exercised option grant, and no new option awards were reported. Because the activity was executed under an established 10b5-1 plan and represents less than 8% of Day’s reported ownership, the filing appears routine. Investors should nonetheless note the CFO’s decision to monetize a portion of his stake at a price materially above the option strike, potentially signalling confidence in capturing value or addressing personal liquidity needs rather than a fundamental view of Magnite’s prospects.

Positive

• CFO retains 443,528 shares after the sale, maintaining significant equity alignment with shareholders.
• Transaction executed under a Rule 10b5-1 plan, demonstrating adherence to governance best practices and reducing information-risk concerns.

Negative

• Insider sale of $0.7 M worth of stock may be perceived as profit-taking, potentially raising mild investor concern about near-term valuation.

Insights

Financial Analyst

TL;DR: CFO exercised options at $4.92, sold at $18.95, still holds 444k shares; routine 10b5-1 trade, neutral signal.

The trade converts option compensation into cash while maintaining a meaningful ownership position. Proceeds (~$0.7 M) are immaterial relative to Magnite’s market cap and do not alter capital structure. Because the transaction was pre-planned and equals only a mid-single-digit percentage of Day’s holdings, it neither suggests imminent downside nor conveys a strong bullish message. From a valuation standpoint, dilution is negligible—shares were already counted in fully diluted share count. Absent accompanying operational data, the filing should be viewed as a housekeeping disclosure rather than a catalyst.

Corporate Governance Expert

TL;DR: Pre-scheduled 10b5-1 sale mitigates governance concern; modest insider selling remains worth monitoring.

Using a 10b5-1 plan adopted months before execution reduces the risk of information asymmetry and aligns with best-practice governance protocols. The sale, however, does represent insider profit-taking near recent highs, and cumulative selling patterns could weigh on investor sentiment if repeated. The retained 443 k share balance still aligns management incentives with shareholders, tempering any negative interpretation.

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^*

Day David

(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)
	CHIEF FINANCIAL OFFICER

3. Date of Earliest Transaction (Month/Day/Year)
06/18/2025

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	06/18/2025		M(1)		38,146	A	$4.92	481,674	D
Common Stock	06/18/2025		S(1)		38,146	D	$18.95	443,528	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
Employee Stock Option (Right to Buy)	$4.92	06/18/2025		M(1)			38,146	(2)	02/20/2029	Common Stock	38,146	$0(3)	0	D

Explanation of Responses:

1. The reported transactions were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 13, 2025.

2. 25% of the stock options vested on February 1, 2020 and the remaining option shares vested in 36 equal installments each calendar month thereafter.

3. Granted as compensation for services.

	/s/ Aaron Saltz, attorney-in-fact	06/20/2025
	** 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.
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FAQ

How many Magnite (MGNI) shares did CFO David Day sell on 18 June 2025?

He sold 38,146 shares of common stock.

At what price were the Magnite shares sold according to this Form 4?

The shares were sold at an average price of $18.95 each.

What was the exercise price of the options converted in the transaction?

The employee stock options were exercised at $4.92 per share.

How many Magnite shares does the CFO still own after the reported sale?

David Day beneficially owns 443,528 shares directly following the transaction.

Was this insider sale conducted under a Rule 10b5-1 trading plan?

Yes, the filing states the transactions were executed under a 10b5-1 plan adopted on 13 March 2025.