Katie Seitz Evans - 09 Jan 2026 Form 4 Insider Report for MAGNITE, INC. (MGNI)

Reporting relationship: President, Operations
Issuer ticker: MGNI
Reported as of: 09 Jan 2026
Net transaction value: -$433,938
SEC form: 4
Accepted by SEC: 12 Jan 2026, 16:30:13 UTC
Prior SEC filing: 05 Jan 2026
Next SEC filing: 18 Feb 2026
Source filing: View source filing
Reporting owner signature: /s/ Aaron Saltz, attorney-in-fact

Key filing fact

Katie Seitz Evans filed Form 4 for MAGNITE, INC. (MGNI) on 12 Jan 2026.

Key facts

This page summarizes Katie Seitz Evans's Form 4 filing for MAGNITE, INC. (MGNI).
3 reported transactions and 1 derivative row are listed below.
Accepted by SEC: 12 Jan 2026, 16:30.

Change

Previous filing in this sequence was filed on 05 Jan 2026.
Current net transaction value: -$433,938.

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 0001700262 Primary reporting owner

Evans Katie Seitz

Relationship: President, Operations
Address: C/O MAGNITE, INC., 1250 BROADWAY, 9TH FLOOR, NEW YORK
Signature: /s/ Aaron Saltz, attorney-in-fact
Signature date: 12 Jan 2026

Reported non-derivative transactions

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

MGNI transaction

Common Stock

Options Exercise

Transaction value: $0
Shares: +51,300
Change %: +10%
Price: $0.000000
Shares after: 562,308
Date: 09 Jan 2026
Ownership: Direct
Footnotes: F1

MGNI transaction

Common Stock

Tax liability

Transaction value: $433,938
Shares: -26,836
Change %: -4.8%
Price: $16.17
Shares after: 535,472
Date: 09 Jan 2026
Ownership: Direct
Footnotes: F2

Reported derivative securities

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

MGNI transaction Derivative

Performance Stock Units

Options Exercise

Transaction value: $0
Shares: -51,300
Change %: -100%
Price: $0.000000
Shares after: 0
Date: 09 Jan 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 51,300
Exercise price
Footnotes: F1, F3, F4

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

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 4 footnotes

Footnote F1

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

Footnote F2

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 the performance stock units ("PSUs") being reported herein.

Footnote F3

Each PSU represents a contingent right to receive, on vesting, one share of the Issuer's common stock, subject to Issuer performance as more specifically described in Footnote 4 herein.

Footnote F4

Vesting of the PSU was determined based on the Issuer's total stockholder return ("TSR") for the three-year period beginning on January 1, 2023 relative to the TSRs of the companies in the Russell 2000 index over that period. The number of PSUs reported in column 5 on the Form 4 filed with the Securities and Exchange Commission on January 4, 2023 reflected the target number of PSUs initially subject to the award. The award was eligible to vest as to 0% to 150% of the target number of PSUs. On January 9, 2026, the Compensation Committee of the Issuer's Board of Directors determined that, based on 126.35% achievement, the Reporting Person actually vested 51,300 shares.