[144] Magnite, Inc. SEC Filing

Rhea-AI Filing Summary

Insider sale notice for Magnite, Inc. (MGNI): This Form 144 reports a proposed sale of 20,000 common shares through Morgan Stanley Smith Barney with an aggregate market value of $492,148.00, with an approximate sale date of 09/09/2025 on NASDAQ. The filing lists recent acquisitions of the shares: purchases via the Employee Stock Purchase Plan on 05/15/2025 and prior ESPP and restricted stock vesting dates between 2023 and 2025. The filer also disclosed sales earlier in September and August 2025 totaling 40,201 shares with gross proceeds shown. The notice includes the signer’s representation of no undisclosed material adverse information.

Positive

• Compliance disclosure filed under Rule 144, providing transparency on insider sales and acquisitions
• Shares acquired via ESPP and registered plan vesting, indicating standard employee compensation sources

Negative

• Insider plans to sell 20,000 shares (aggregate market value $492,148), which may be viewed by some investors as insider liquidity
• Recent prior sales in Aug–Sep 2025 total 40,201 shares with stated gross proceeds, showing significant insider sell activity

Insights

Securities Analyst

TL;DR: Routine Rule 144 notice showing an insider’s planned sale and recent transactions; disclosure is compliance-focused, not a company performance statement.

The filing documents a proposed sale of 20,000 shares valued at $492,148 and lists recent acquisitions (ESPP purchases and restricted stock vesting) from 2023–2025, indicating these shares were acquired under standard employee programs. It also records prior sales of 20,000, 9,315, and 10,886 shares in Aug–Sep 2025 with stated gross proceeds. For investors, this is primarily a transparency and insider-liquidity signal rather than a direct measure of corporate operational performance; no earnings, guidance, or corporate actions are disclosed here.

Corporate Governance Expert

TL;DR: The filing reflects compliance with SEC resale rules and contains standard representations about material nonpublic information.

The Form 144 shows the seller relied on shares acquired through an ESPP and restricted stock vesting under registered plans, and it includes the required attestation about lacking undisclosed material adverse information. The presence of multiple recent sales and the planned sale should be interpreted as insider liquidity activity; the filing itself does not provide evidence of governance issues or regulatory concerns.

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

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	20000	492148.00	142399305	09/09/2025	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	05/15/2025	Shares Purchased through Employee Stock Purchase Plan	Issuer			1577	05/15/2025	Cash
Common	02/15/2025	Restricted stock vesting under a registered plan	Issuer			5843	02/15/2025	Compensation
Common	05/15/2025	Restricted stock vesting under a registered plan	Issuer			4178	05/15/2025	Compensation
Common	05/15/2024	Shares Purchased through Employee Stock Purchase Plan	Issuer			3272	05/15/2024	Cash
Common	05/15/2023	Shares Purchased through Employee Stock Purchase Plan	Issuer			4456	05/15/2023	Cash
Common	06/01/2023	Restricted stock vesting under a registered plan	Issuer			674	06/01/2023	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
SEAN BUCKLEY 1250 Broadway, 15th Floor New York NY 10001	Common	09/08/2025	20000	511214.00
SEAN P BUCKLEY 1250 Broadway, 15th Floor New York NY 10001	Common	08/19/2025	9315	218152.18
SEAN P BUCKLEY 1250 Broadway, 15th Floor New York NY 10001	Common	08/18/2025	10886	259667.02

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 does the Form 144 for Magnite (MGNI) report?

It reports a proposed sale of 20,000 common shares valued at $492,148.00, with an approximate sale date of 09/09/2025 on NASDAQ.

How were the shares being sold acquired?

The filing shows the shares were acquired through the Employee Stock Purchase Plan and by restricted stock vesting under registered plans between 2023 and 2025.

Has the filer sold other MGNI shares recently?

Yes. The filing discloses prior sales on 09/08/2025 (20,000 shares), 08/19/2025 (9,315 shares), and 08/18/2025 (10,886 shares) with gross proceeds shown.

Who is the broker handling the proposed sale?

The broker named is Morgan Stanley Smith Barney LLC, Executive Financial Services, 1 New York Plaza, 8th Floor, New York, NY 10004.

Does the Form 144 include any statements about undisclosed material information?

Yes. The signer represents that they do not know any material adverse information about the issuer that has not been publicly disclosed.