STOCK TITAN

Magnite (MGNI) CEO logs tax-withholding forfeiture of 10,404 shares on Form 4

Filing Impact
(High)
Filing Sentiment
(Neutral)
Form Type
4

Rhea-AI Filing Summary

MAGNITE, INC. CEO Michael G. Barrett reported a routine tax-related share forfeiture. On May 15, 2026, 10,404 shares of common stock were disposed of at an indicated value of $12.82 per share to satisfy tax withholding obligations tied to vesting restricted stock units.

The filing notes this was a non-discretionary forfeiture mandated by the company’s arrangement, not an open-market sale. After this transaction, Barrett directly holds 403,074 shares of Magnite common stock, which includes 1,316 shares acquired the same day under the company’s Employee Stock Purchase Plan.

Positive

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Insider BARRETT MICHAEL G.
Role CEO
Type Security Shares Price Value
Tax Withholding Common Stock 10,404 $12.82 $133K
Holdings After Transaction: Common Stock — 403,074 shares (Direct, null)
Footnotes (1)
  1. Represents the non-discretionary forfeiture of shares on behalf of the Reporting Person pursuant to an arrangement mandated by the Issuer to cover the tax withholding obligations associated with the vesting of restricted stock units. Includes 1,316 shares acquired by the Reporting Person on May 15, 2026 under the Issuer's Employee Stock Purchase Plan.
Tax-withholding shares 10,404 shares Disposed on May 15, 2026 to cover RSU tax
Indicated price per share $12.82/share Value used for 10,404-share tax disposition
Shares held after transaction 403,074 shares Direct MAGNITE holdings following Form 4 event
ESPP shares acquired 1,316 shares Acquired May 15, 2026 under Employee Stock Purchase Plan
restricted stock units financial
"cover the tax withholding obligations associated with the vesting of restricted stock units"
Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.
Employee Stock Purchase Plan financial
"shares acquired by the Reporting Person on May 15, 2026 under the Issuer's Employee Stock Purchase Plan"
An employee stock purchase plan is a company program that lets workers buy shares through small payroll deductions, often at a discount to the market price and after a set offering period. Think of it like a workplace savings plan that turns into ownership: it encourages employees to share in the company’s success and can create predictable buying or selling of stock that investors watch because it affects supply, demand and employee incentives.
tax withholding obligations financial
"to cover the tax withholding obligations associated with the vesting of restricted stock units"
SEC Form 4
FORM 4UNITED 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).
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, 9TH FLOOR

(Street)
NEW YORK NEW YORK 10001

(City)(State)(Zip)

UNITED STATES

(Country)
2. Issuer Name and Ticker or Trading Symbol
MAGNITE, INC. [ MGNI ]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
XDirector10% Owner
XOfficer (give title below)Other (specify below)
CEO
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
05/15/2026
6. Individual or Joint/Group Filing (Check Applicable Line)
XForm filed by One Reporting Person
Form filed by More than One Reporting Person
4. If Amendment, Date of Original Filed (Month/Day/Year)

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)
CodeVAmount(A) or (D)Price
Common Stock05/15/2026F(1)10,404D$12.82403,074(2)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)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Explanation of Responses:
1. Represents the non-discretionary forfeiture of shares on behalf of the Reporting Person pursuant to an arrangement mandated by the Issuer to cover the tax withholding obligations associated with the vesting of restricted stock units.
2. Includes 1,316 shares acquired by the Reporting Person on May 15, 2026 under the Issuer's Employee Stock Purchase Plan.
/s/ Aaron Saltz, attorney-in-fact05/19/2026
** Signature of Reporting PersonDate
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.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transaction did MAGNITE (MGNI) CEO Michael Barrett report?

Michael Barrett reported a tax-withholding disposition of 10,404 MAGNITE shares. The shares were forfeited on May 15, 2026 to cover tax obligations from vesting restricted stock units under a company-mandated arrangement.

Was the MAGNITE (MGNI) CEO’s Form 4 transaction an open-market sale?

No, the Form 4 describes a non-discretionary forfeiture to cover taxes. Shares were automatically delivered to satisfy tax withholding tied to RSU vesting, rather than being sold by the CEO in the open market.

How many MAGNITE (MGNI) shares does the CEO hold after this Form 4?

After the tax-withholding disposition, Michael Barrett directly holds 403,074 MAGNITE shares. This total includes 1,316 shares he acquired on May 15, 2026 through the company’s Employee Stock Purchase Plan.

What price per share is shown in MAGNITE (MGNI) CEO’s tax-withholding transaction?

The Form 4 lists a transaction price of $12.82 per MAGNITE share. This value is used to calculate the tax-withholding disposition of 10,404 shares associated with the vesting of restricted stock units.

What do the MAGNITE (MGNI) Form 4 footnotes say about the CEO’s shares?

The footnotes explain that 10,404 shares were forfeited to cover tax withholding on RSU vesting. They also state that the CEO acquired 1,316 additional shares on May 15, 2026 under MAGNITE’s Employee Stock Purchase Plan.