Michael G. Barrett - 01 Jan 2026 Form 4 Insider Report for MAGNITE, INC. (MGNI)

Reporting relationship: CEO, Director
Issuer ticker: MGNI
Reported as of: 01 Jan 2026
Net transaction value: $0
SEC form: 4
Accepted by SEC: 05 Jan 2026, 19:19:58 UTC
Prior SEC filing: 18 Nov 2025
Next SEC filing: 12 Jan 2026
Source filing: View source filing
Reporting owner signature: /s/ Aaron Saltz, attorney-in-fact

Key filing fact

Michael G. Barrett filed Form 4 for MAGNITE, INC. (MGNI) on 05 Jan 2026.

Key facts

This page summarizes Michael G. Barrett's Form 4 filing for MAGNITE, INC. (MGNI).
3 reported transactions and 2 derivative rows are listed below.
Accepted by SEC: 05 Jan 2026, 19:19.

Change

Previous filing in this sequence was filed on 18 Nov 2025.
Current net transaction value: $0.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001100612 Primary reporting owner

BARRETT MICHAEL G.

Relationship: CEO, Director
Address: C/O MAGNITE, INC., 1250 BROADWAY, 9TH FLOOR, NEW YORK
Signature: /s/ Aaron Saltz, attorney-in-fact
Signature date: 05 Jan 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

MGNI transaction

Common Stock

Award

Transaction value: $0
Shares: +94,044
Change %: +40%
Price: $0.000000
Shares after: 331,703
Date: 01 Jan 2026
Ownership: Direct
Footnotes: F1, F2

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

MGNI transaction Derivative

Performance Stock Units

Award

Transaction value: $0
Shares: +122,864
Change %
Price: $0.000000
Shares after: 122,864
Date: 01 Jan 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 122,864
Exercise price
Footnotes: F2, F3, F4

MGNI transaction Derivative

Stock Option (Right to Buy)

Award

Transaction value: $0
Shares: +90,909
Change %
Price: $0.000000
Shares after: 90,909
Date: 01 Jan 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 90,909
Exercise price: $16.23
Footnotes: F2, F5

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 5 footnotes

Footnote F1

Represents restricted stock units that vest as follows: 25,470 on February 15, 2027, 5,878 on each May 15, August 15, November 15, and February 15 thereafter until November 15, 2029 and 3,916 on February 15, 2030, subject to continued service to the Issuer through each vesting date. This equity grant may be subject to accelerated vesting in the event the Reporting Person's employment is terminated under certain circumstances.

Footnote F2

Equity grant under the Company's Amended and Restated 2014 Equity Incentive Plan.

Footnote F3

Each performance stock unit ("PSU") represents a contingent right to receive on vesting one share of the Issuer's common stock.

Footnote F4

The PSUs will generally vest on the three-year anniversary of the grant date of the award subject to the Reporting Person's continued service through such date. The number of shares vested will be determined based on the Issuer's total stockholder return ("TSR") relative to the TSRs of the companies in the Russell 2000 index for the three year-period beginning January 1, 2026, as well as certain interim measurements based on relative TSR for the one-year and two-year periods beginning on January 1, 2026. The number of PSUs reported in column 5 reflects the target number of PSUs subject to the award. The award is eligible to vest as to 0% to 150% of the target number of PSUs.

Footnote F5

25% of the total number of shares underlying this option will vest on January 1, 2027 and the remaining shares vest 1/36 per month over the next 36 months thereafter, subject to continued service to the Issuer through each vesting date. This equity grant may be subject to accelerated vesting in the event the Reporting Person's employment is terminated under certain circumstances.