MGNI Form 4: Paul Caine Sells 7,500 Shares via 10b5-1 Plan

Rhea-AI Filing Summary

Magnite, Inc. (MGNI) director Paul Caine sold 7,500 shares of common stock on 08/25/2025 at $25.00 per share under a Rule 10b5-1 trading plan adopted on 08/15/2024. After the reported sale, the filing shows Mr. Caine beneficially owns 171,103 shares, reported in a Form 4 filed as an individual reporting person. The transaction is coded S(1) indicating a sale pursuant to a pre-established trading arrangement. The Form 4 was executed by attorney-in-fact Aaron Saltz on 08/26/2025.

Positive

• Transaction executed under a Rule 10b5-1 trading plan, providing a documented framework for the sale
• Filing discloses post-transaction beneficial ownership (171,103 shares), supporting transparency and Section 16 compliance

Negative

• Director disposed of 7,500 shares, reducing his direct stake by that amount
• Sale may be interpreted by some investors as insider liquidity, though no intent or company-specific reason is disclosed

Insights

Corporate Governance Expert

TL;DR: Insider sale executed under a 10b5-1 plan reduces signaling risk but decreases the director's direct stake by 7,500 shares.

The Form 4 reports a planned sale under a Rule 10b5-1 arrangement, which typically aims to provide an affirmative defense to insider trading claims by following predetermined rules. The director retains 171,103 shares after the transaction, and the sale price was $25.00 per share. From a governance perspective, the presence of a 10b5-1 plan and the clear reporting indicate compliance with Section 16 reporting obligations and transparency around insider dispositions.

Securities Analyst

TL;DR: Director sold 7,500 shares at $25 under a pre-set plan; the trade is routine disclosure rather than material corporate news.

The sale is coded S(1) and tied to a plan adopted 08/15/2024, suggesting execution per an established schedule. The remaining beneficial ownership of 171,103 shares is disclosed. This Form 4 provides required transparency about insider holdings and transactions but contains no earnings or operational data affecting company valuation.

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)
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)		7,500	D	$25	171,103	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. This sale was made pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on August 15, 2024.

	/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 did Magnite director Paul Caine report on Form 4 (MGNI)?

The Form 4 reports that Paul Caine sold 7,500 shares of Magnite common stock on 08/25/2025 at $25.00 per share under a Rule 10b5-1 plan.

How many Magnite (MGNI) shares does Paul Caine beneficially own after the sale?

Following the reported transaction, the filing shows Paul Caine beneficially owns 171,103 shares.

Was the sale by the director part of a prearranged trading plan?

Yes. The sale was made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on 08/15/2024.

Who signed the Form 4 for this transaction?

The Form 4 was executed by Aaron Saltz, attorney-in-fact, on 08/26/2025.

What transaction code is used for the sale on the Form 4?

The sale is coded S(1), indicating a sale pursuant to a predefined plan or arrangement.