MGNI Form 4: 5,000-share sale; holdings now 153,603 shares

Rhea-AI Filing Summary

Magnite (MGNI) insider transaction: A company director reported selling 5,000 shares of common stock on 10/24/2025 at $20 per share, according to a Form 4 filing. Following the sale, the reporting person beneficially owns 153,603 shares, held directly.

The filing notes the sale was executed under a Rule 10b5-1 trading plan adopted on August 15, 2024, which allows pre-scheduled trades. The reporting person filed individually, and the role is disclosed as Director.

Insider Trade Summary

Net Seller: 5,000 shares ($100,000)

Net Sell 1 txn

Insider Caine Paul

Role Director

Sold 5,000 shs ($100K)

Type	Security	Shares	Price	Value
Sale	Common Stock	5,000	$20.00	$100K

Holdings After Transaction: Common Stock — 153,603 shares (Direct)

Footnotes (1)

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Form 4 Insider Transactions: What Each Field Means →

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^*

Caine Paul

(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)

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

3. Date of Earliest Transaction (Month/Day/Year)
10/24/2025

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	10/24/2025		S(1)		5,000	D	$20	153,603	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 sales were made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 15, 2024.

	/s/ Aaron Saltz, attorney-in-fact	10/28/2025
	** 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 activity did MGNI report?

A Director sold 5,000 shares of Magnite common stock at $20 per share on 10/24/2025.

How many Magnite (MGNI) shares does the insider hold after the sale?

The reporting person beneficially owns 153,603 shares following the transaction, held directly.

Was the MGNI insider sale under a Rule 10b5-1 plan?

Yes. The sale was made under a Rule 10b5-1 trading plan adopted on August 15, 2024.

What was the transaction code on the Form 4 for MGNI?

The transaction was coded S, indicating an open market sale.

Who filed the MGNI Form 4 and in what capacity?

The filing was made by one reporting person, identified as a Director of Magnite.

What is the ownership form after the MGNI transaction?

Ownership is listed as Direct (D).