Magnite Form 4: Barrett offloads 75k shares, retains 656k stake

Rhea-AI Filing Summary

Magnite, Inc. (MGNI) Form 4 filing: CEO & Director Michael G. Barrett disclosed two open-market sales executed under a Rule 10b5-1 trading plan adopted on 03/12/2025.

• 06/16/2025: 45,000 shares of common stock sold at a $17.76 weighted-average price
• 06/18/2025: 30,000 shares sold at $19.00.

Total shares sold: 75,000. Following the transactions, Barrett owns 656,708 shares directly.

The Form notes that detailed price breakdowns are available upon SEC request. No derivative security activity was reported.

The sales reduce Barrett’s direct holdings by roughly 10%

Positive

• Sales executed under a Rule 10b5-1 trading plan, reducing concerns about use of material non-public information.
• CEO retains 656,708 shares, indicating continued significant ownership alignment with shareholders.

Negative

• CEO disposed of 75,000 shares, reducing his direct stake by roughly 10% and potentially signaling lowered confidence or liquidity needs.
• Transactions occurred at $17.76–$19.00, which may establish an informal near-term valuation ceiling for the stock.

Insights

Financial Analyst

TL;DR: CEO sells 75k shares (~10%) via 10b5-1 plan; neutral signal due to pre-planning, but watch insider-sale trend.

The filing shows two modest-sized sales totaling 75,000 shares at $17.76–$19.00, leaving 656,708 shares outstanding. Because the transactions were executed under a Rule 10b5-1 plan adopted months earlier, timing risk tied to undisclosed information is lower. The divestiture is roughly 10% of his direct stake—large enough to notice yet not large enough to imply a material change in confidence or control. No options were exercised and no derivatives were involved, so the disposition is purely cash-driven. Overall, I view the impact on valuation as neutral; however, persistent insider selling could pressure sentiment if pattern continues.

Corporate Governance Expert

TL;DR: Pre-scheduled insider sale under 10b5-1 limits governance concern, but investors may question optics of CEO trimming stake.

From a governance standpoint, the critical protection is Barrett’s 10b5-1 plan, which provides an affirmative defense against trading on material non-public information. The plan’s adoption date (03/12/2025) appears well before the transactions, satisfying best-practice cooling-off expectations. Remaining ownership of 656,708 shares keeps his incentives aligned with shareholders. Still, any CEO sale exceeding 5% of holdings can draw scrutiny, and this ~10% reduction will likely trigger perception risk if company performance falters. I assign a mildly negative sentiment because optics alone can influence investor confidence.

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^*

BARRETT MICHAEL G.

(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
X	Officer (give title below)		Other (specify below)
	CEO

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		S(1)		45,000	D	$17.76(2)	686,708	D
Common Stock	06/18/2025		S(1)		30,000	D	$19	656,708	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. The reported transactions were effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 12, 2025.

2. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $17.30 to $18.00, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

	/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 MGNI shares did CEO Michael Barrett sell?

He sold 75,000 shares across two transactions on 06/16/2025 and 06/18/2025.

At what prices were the MGNI shares sold?

Shares were sold at a weighted average of $17.76 $19.00.

Does the filing indicate use of a 10b5-1 trading plan?

Yes. The sales were executed under a Rule 10b5-1 plan adopted on 03/12/2025.

What is Michael Barrett’s MGNI share ownership after the transactions?

He directly owns 656,708 MGNI shares following the reported sales.

Were any derivative securities involved in this Form 4?

No. No options or other derivatives were exercised or disposed of in this filing.