Magnite (MGNI) CTO sells 7,649 shares via Rule 10b5-1 trading plan

Q: What did MAGNITE (MGNI) report in this Form 4 filing?

MAGNITE reported that CTO David Buonasera sold 7,649 shares of common stock on August 6, 2026 in three open-market transactions executed under a Rule 10b5-1 trading plan adopted on September 11, 2025.

Q: How many MAGNITE (MGNI) shares did CTO David Buonasera sell?

CTO David Buonasera sold a total of 7,649 shares of MAGNITE common stock. The transactions occurred on August 6, 2026 and were reported as three separate open-market sales under a pre-established Rule 10b5-1 trading plan .

Q: At what prices were MAGNITE (MGNI) shares sold in this Form 4?

The reported sales occurred at prices between $22.72 and $25.00 per share. One tranche had a weighted average price of $22.81 , another was at $24.00 , and the final tranche was sold at $25.00 per share.

Q: How were the 4,176 MAGNITE (MGNI) shares priced in the largest tranche?

The 4,176 shares in the largest tranche were sold at a weighted average price of $22.81 per share. The filing notes these shares were sold in multiple trades at prices ranging from $22.72 to $23.00 , inclusive.

Filing Impact

(Moderate)

Filing Sentiment

(Negative)

Form Type

Rhea-AI Filing Summary

MAGNITE, INC. Chief Technology Officer David Buonasera reported selling 7,649 shares of common stock on August 6, 2026 in three open-market transactions under a Rule 10b5-1 trading plan adopted on September 11, 2025. Sale prices ranged from $22.72 to $25.00 per share.

Insider Trade Summary 10b5-1

Net Seller: 7,649 shares

Net Sell 3 txns

Insider Buonasera David

Role CHIEF TECHNOLOGY OFFICER

Sold 7,649 shs ($179K)

Type	Security	Shares	Price	Value
Sale	Common Stock ^{F1, F2}	4,176	$22.81	$95K
Sale	Common Stock ^F1	2,602	$24.00	$62K
Sale	Common Stock ^F1	871	$25.00	$22K

Holdings After Transaction: Common Stock — 260,836 shares (Direct)

Footnotes (2)

F1. The reported transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 11, 2025.
F2. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $22.72 to $23.00, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote to this Form 4.

Key Figures

Total shares sold: 7,649 shares Shares sold at $22.81 weighted average: 4,176 shares Shares sold at $24.00: 2,602 shares +2 more

5 metrics

Total shares sold 7,649 shares Common stock sold by CTO David Buonasera on August 6, 2026

Shares sold at $22.81 weighted average 4,176 shares Open-market sale at weighted average price $22.81 per share

Shares sold at $24.00 2,602 shares Open-market sale at $24.00 per share

Shares sold at $25.00 871 shares Open-market sale at $25.00 per share

Price range for weighted average sale $22.72–$23.00 Range of prices for trades included in the $22.81 weighted average sale

Key Terms

Rule 10b5-1 trading plan, weighted average price, open market or private transaction

3 terms

Rule 10b5-1 trading plan financial

"The reported transaction was effected pursuant to a Rule 10b5-1 trading plan adopted..."

A Rule 10b5-1 trading plan is a pre-arranged schedule that allows company insiders to buy or sell stock at specific times, even if they have inside information. It helps prevent accusations of unfair trading by making these transactions look planned and transparent, rather than sneaky or illegal.

weighted average price financial

"The price reported in Column 4 is a weighted average price. These shares were sold..."

Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.

open market or private transaction financial

"Transaction code description: Sale in open market or private transaction"

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Form 4 Insider Transactions: What Each Field Means →

Available on EDGAR 08/07/2026 - 05:10 PM Accepted by SEC EDGAR 08/07/2026 - 05:09 PM

FAQ

What did MAGNITE (MGNI) report in this Form 4 filing?

MAGNITE reported that CTO David Buonasera sold 7,649 shares of common stock on August 6, 2026 in three open-market transactions executed under a Rule 10b5-1 trading plan adopted on September 11, 2025.

How many MAGNITE (MGNI) shares did CTO David Buonasera sell?

CTO David Buonasera sold a total of 7,649 shares of MAGNITE common stock. The transactions occurred on August 6, 2026 and were reported as three separate open-market sales under a pre-established Rule 10b5-1 trading plan.

At what prices were MAGNITE (MGNI) shares sold in this Form 4?

The reported sales occurred at prices between $22.72 and $25.00 per share. One tranche had a weighted average price of $22.81, another was at $24.00, and the final tranche was sold at $25.00 per share.

Was the MAGNITE (MGNI) insider sale made under a Rule 10b5-1 plan?

Yes. The filing states the transactions were effected pursuant to a Rule 10b5-1 trading plan adopted by David Buonasera on September 11, 2025. The plan governed the August 6, 2026 open-market sales reported here.

How were the 4,176 MAGNITE (MGNI) shares priced in the largest tranche?

The 4,176 shares in the largest tranche were sold at a weighted average price of $22.81 per share. The filing notes these shares were sold in multiple trades at prices ranging from $22.72 to $23.00, inclusive.

SEC Form 4

FORM 4

UNITED 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^*

Buonasera David

(Last)

(First)

(Middle)

C/O MAGNITE, INC.

1250 BROADWAY, 9TH FLOOR

(Street)

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)

	Director	10% Owner
X	Officer (give title below)	Other (specify below)
	CHIEF TECHNOLOGY OFFICER

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
08/06/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form 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)
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	Code	V	Amount	(A) or (D)	Price		6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
Common Stock	08/06/2026		S⁽¹⁾		4,176	D	$22.81⁽²⁾	264,309	D
Common Stock	08/06/2026		S⁽¹⁾		2,602	D	$24	261,707	D
Common Stock	08/06/2026		S⁽¹⁾		871	D	$25	260,836	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)
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)	Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	8. Price of Derivative Security (Instr. 5)		10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)

Explanation of Responses:

1. The reported transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on September 11, 2025.

2. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $22.72 to $23.00, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote to this Form 4.

Remarks:

	/s/ Aaron Saltz, attorney-in-fact	08/07/2026
	** Signature of Reporting Person	Date
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)

Source: View Original Filing on SEC EDGAR