MGNI insider sold 130,828 shares in June; 14,518-share RSU sale planned

Rhea-AI Filing Summary

Magnite, Inc. (MGNI) Form 144 filing reports proposed and recent insider sales. An insider plans to sell 14,518 common shares via Morgan Stanley on or about 08/18/2025; those shares were acquired as restricted stock units on 08/15/2025 and will be settled as equity compensation. The filing also discloses four prior sales by the same person in June 2025 totaling 130,828 shares for aggregate gross proceeds of $2,652,320.70. The issuer’s total shares outstanding listed is 142,399,305, so the proposed sale represents a small fraction of outstanding stock. The filer certifies no undisclosed material adverse information is known.

Positive

• None.

Negative

• Insider sold 130,828 shares in June 2025 across four transactions, which may be perceived negatively by some investors even though proceeds appear to be from routine sales ($2,652,320.70 total).
• Proposed sale of recently acquired RSUs (14,518 shares) suggests immediate disposition upon vesting rather than long-term holding, which some market participants may view unfavorably.

Insights

Securities Analyst

TL;DR: Insider selling is notable but represents a small percentage of shares outstanding; likely routine liquidity from compensation.

The filing shows a proposed sale of 14,518 shares acquired as restricted stock units and multiple June 2025 dispositions totaling 130,828 shares. Combined June gross proceeds of prior sales were $2,652,320.70. Relative to the reported 142.4 million shares outstanding, these transactions are immaterial to market capitalization. This pattern is consistent with post-vesting disposition of equity compensation and scheduled sales rather than a company-specific disclosure of weakness. Market impact should be limited absent other material information.

Corporate Governance Expert

TL;DR: Disclosure complies with Rule 144; filings show standard insider reporting and a representation about material info.

The notice properly identifies the broker (Morgan Stanley Smith Barney LLC), the acquisition type (Restricted Stock Unit), and that the transaction arises from equity compensation. The signer affirms they are unaware of undisclosed material adverse information, consistent with Form 144 attestations. Governance-wise, the filing raises routine transparency points but no governance red flags are evident from the provided content alone.

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK
Filer CCC
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer

SEC File Number

Address of Issuer

Phone

Name of Person for Whose Account the Securities are To Be Sold

See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.

Relationship to Issuer

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common	Morgan Stanley Smith Barney LLC Executive Financial Services 1 New York Plaza 8th Floor New York NY 10004	14518	344076.60	142399305	08/18/2025	NASDAQ

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common	08/15/2025	Restricted Stock Unit- See Remarks	Issuer			14518	08/15/2025	Equity Compensation

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
David Day c/o Magnite, Inc. 1250 Broadway, 15th Floor New York NY 10001	Common	06/30/2025	21682	477004.00
David Day c/o Magnite, Inc. 1250 Broadway, 15th Floor New York NY 10001	Common	06/26/2025	36000	754200.00
David Day c/o Magnite, Inc. 1250 Broadway, 15th Floor New York NY 10001	Common	06/24/2025	35000	698250.00
David Day c/o Magnite, Inc. 1250 Broadway, 15th Floor New York NY 10001	Common	06/18/2025	38146	722866.70

144: Remarks and Signature

Remarks

Date of Notice

ATTENTION:

The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.

Signature

ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)

FAQ

What insider sales does Magnite (MGNI) report in this Form 144?

The filing discloses four sales in June 2025 totaling 130,828 shares and a proposed sale of 14,518 shares scheduled for 08/18/2025.

How were the 14,518 shares acquired according to the filing?

Those shares were acquired on 08/15/2025 as Restricted Stock Units and the payment/settlement is shown as Equity Compensation.

Through which broker will the proposed sale be executed?

The proposed sale is to be executed through Morgan Stanley Smith Barney LLC (Executive Financial Services, 1 New York Plaza, 8th Floor, New York, NY).

How do the disclosed sales compare to Magnite's shares outstanding?

The filing lists 142,399,305 shares outstanding; the proposed 14,518-share sale represents a very small fraction of total outstanding shares.

What certification does the filer make in the Form 144?

The person signing the notice represents they do not know any material adverse information regarding the issuer that has not been publicly disclosed.