[144] MAGNITE, INC. SEC Filing

Rhea-AI Filing Summary

Insider sale notice for Magnite, Inc. (MGNI). This Form 144 reports a proposed sale of 7,500 common shares to be executed through Morgan Stanley Smith Barney LLC on 09/19/2025 with an aggregate market value of $179,100. The shares were acquired as restricted stock units on 06/01/2018. The filing notes 142,399,305 shares outstanding for the class. The filer discloses multiple prior 10b5-1 plan sales in the past three months totaling 27,500 shares and gross proceeds shown for each trade. The notice includes the standard representation that the seller is unaware of undisclosed material adverse information.

Positive

• Full disclosure of sale details including broker, number of shares, planned sale date, and aggregate market value
• History of prior 10b5-1 sales is provided, showing a documented trading plan and transparency

Negative

• Insider is selling shares, which some investors may view negatively despite small size relative to outstanding shares

Insights

Securities Analyst

TL;DR: Routine insider sale filing showing small-volume RSU sale and several recent 10b5-1 trades; not material to company capitalization.

The Form 144 documents a proposed sale of 7,500 common shares via Morgan Stanley under Rule 144, with the securities originally issued as restricted stock units on 06/01/2018. The filing also lists five prior 10b5-1 plan sales in the prior three months totaling 27,500 shares and shows gross proceeds for each transaction. Relative to the reported 142.4 million shares outstanding, these transactions represent an immaterial fraction of outstanding equity, suggesting limited direct impact on market capitalization or control. Disclosure appears complete for the sale particulars presented.

Compliance/Risk Analyst

TL;DR: Compliance details and 10b5-1 history are provided; representation about no undisclosed material information is included.

The filing includes broker information, acquisition type (RSUs), acquisition and proposed sale dates, and a standard signature-attestation regarding undisclosed material adverse information. Multiple prior 10b5-1 sales are itemized with dates and proceeds, supporting a pattern of planned dispositions. From a regulatory perspective, the notice meets Rule 144 disclosure elements shown; there is no indication within this document of noncompliance or procedural irregularity.

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	7500	179100.00	142399305	09/19/2025	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	06/01/2018	Restricted Stock Units	Issuer			7500	06/01/2018	N/A

* 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
10b5-1 Sales for PAUL CAINE 1250 Broadway 15th Floor New York NY 10001	Common	09/10/2025	5000	118006.50
10b5-1 Sales for PAUL CAINE 1250 Broadway 15th Floor New York NY 10001	Common	08/25/2025	7500	187500.00
10b5-1 Sales for PAUL CAINE 1250 Broadway 15th Floor New York NY 10001	Common	08/11/2025	5000	111427.50
10b5-1 Sales for PAUL CAINE 1250 Broadway 15th Floor New York NY 10001	Common	07/10/2025	5000	117636.50
10b5-1 Sales for PAUL CAINE 1250 Broadway 15th Floor New York NY 10001	Common	06/24/2025	5000	100000.00

144: Remarks and Signature

Remarks

Date of Notice

Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1

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

How many Magnite (MGNI) shares are proposed for sale in this Form 144?

The notice proposes the sale of 7,500 common shares.

When is the proposed sale date for the MGNI shares?

The Form 144 lists an approximate sale date of 09/19/2025.

How were the shares being sold originally acquired?

The shares were acquired as restricted stock units (RSUs) on 06/01/2018.

Who is the broker handling the proposed sale?

The broker named is Morgan Stanley Smith Barney LLC with the New York address shown.

What is the aggregate market value reported for the proposed sale?

The aggregate market value is reported as $179,100.00.

Has the filer sold MGNI shares recently?

Yes. The filing lists five prior 10b5-1 plan sales in the past three months totaling 27,500 shares with gross proceeds shown for each trade.