David Buonasera - 01 Jan 2026 Form 4 Insider Report for MAGNITE, INC. (MGNI)

Role: CHIEF TECHNOLOGY OFFICER
Signature: /s/ Aaron Saltz, attorney-in-fact
Issuer symbol: MGNI
Transactions as of: 01 Jan 2026
Net transactions value: $0
Form type: 4
Filing time: 05 Jan 2026, 19:17:56 UTC
Previous filing: 18 Nov 2025
Next filing: 12 Jan 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Buonasera David	CHIEF TECHNOLOGY OFFICER	C/O MAGNITE, INC., 1250 BROADWAY, 9TH FLOOR, NEW YORK	/s/ Aaron Saltz, attorney-in-fact	05 Jan 2026	0001966857

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	MGNI	Common Stock	Award	$0	+76,803	+33%	$0.000000	308,627	01 Jan 2026	Direct	F1, F2

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	MGNI	Performance Stock Units	Award	$0	+25,801		$0.000000	25,801	01 Jan 2026	Common Stock	25,801		Direct	F2, F3, F4

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Represents restricted stock units that vest as follows: 20,801 on February 15, 2027, 4,800 on each May 15, August 15, November 15, and February 15 thereafter until November 15, 2029 and 3,202 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.
F2	Equity grant under the Company's Amended and Restated 2014 Equity Incentive Plan.
F3	Each performance stock unit ("PSU") represents a contingent right to receive on vesting one share of the Issuer's common stock.
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.