Magnite director sells 10,363 shares at $23.76

Magnite director Robert F. Spillane exercised and sold 10,363 shares in an option-related transaction on September 14, 2026.

Rhea-AI Filing Summary

MAGNITE, INC. (MGNI) director Robert F. Spillane exercised stock options for 10,363 shares of common stock on September 14, 2026 at an exercise price of $5.17 per share, then sold 10,363 shares of common stock the same day at a weighted average price of $23.76 per share. The options were fully vested and granted as compensation, and this exercise left no shares remaining under that option award.

Insider Trade Summary

Exercise and Sale: 10,363 shares ($193K approx. pre-tax spread)

Exercise and Sale 3 txns

Insider Spillane Robert F

Role Director

Sold 10,363 shs ($246K)

Approx. gross sale proceeds $246K

Approx. exercise cost $54K

Approx. pre-tax spread $193K

Type	Security	Shares	Price	Value
Exercise	Stock Option (right to buy) F3, F2	10,363	$0.00	$0.00
Exercise	Common Stock	10,363	$5.17	$54K
Sale	Common Stock F1	10,363	$23.76	$246K

Holdings After Transaction: Stock Option (right to buy) — 0 contracts (Direct); Common Stock — 57,715 shares (Direct)

Footnotes (3)

1. F1. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $23.75 to $23.7901, 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.
2. F2. The stock options have fully vested and are immediately exercisable.
3. F3. Granted as compensation for services.

Key Figures

Options exercised: 10,363 shares Exercise price: $5.17 per share Shares sold: 10,363 shares +3 more

6 metrics

Options exercised 10,363 shares Stock options exercised for Magnite common stock on September 14, 2026

Exercise price $5.17 per share Exercise price of stock options for 10,363 shares of Magnite common stock

Shares sold 10,363 shares Magnite common stock sold on September 14, 2026

Weighted average sale price $23.76 per share Shares sold in multiple transactions between $23.75 and $23.7901

Option expiration date May 23, 2027 Expiration date of the exercised stock option grant

Options remaining after exercise 0 options Total stock options under this award following the reported exercise

Key Terms

weighted average price, stock options, immediately exercisable

3 terms

weighted average price financial

"The price reported in Column 4 is a weighted average price."

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.

stock options financial

"The stock options have fully vested and are immediately exercisable."

Stock options are agreements that give a person the right to buy or sell a company's stock at a specific price within a certain time frame. They are often used as a reward or incentive, similar to a coupon that can be used later if the stock price rises, allowing the holder to make a profit.

immediately exercisable financial

"The stock options have fully vested and are immediately exercisable."

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What did MAGNITE, INC. (MGNI) director Robert F. Spillane report on this Form 4?

He reported exercising stock options for 10,363 shares of Magnite common stock at $5.17 per share and selling 10,363 shares of common stock on September 14, 2026 in a related transaction.

How many MGNI shares did Robert F. Spillane sell and at what price?

He sold 10,363 shares of Magnite common stock at a weighted average price of $23.76 per share, with individual sale prices ranging from $23.75 to $23.7901 on September 14, 2026.

What was the exercise price of the options Robert F. Spillane exercised in MGNI?

The stock options he exercised entitled him to acquire Magnite common stock at an exercise price of $5.17 per share, and the options were fully vested and immediately exercisable.

Were the MGNI stock options exercised by Robert F. Spillane compensation-related?

Yes. The filing states that the stock options exercised for 10,363 shares of Magnite common stock were granted as compensation for services.

Was a Rule 10b5-1 trading plan used for Robert F. Spillane’s MGNI transactions?

No. The Form 4 indicates no Rule 10b5-1 trading plan for these transactions, and the footnotes do not reference any such plan.

Does Robert F. Spillane retain any options from this MGNI grant after the transaction?

No. After exercising the stock option for 10,363 shares, the Form 4 shows 0 options remaining under that specific award.

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

Form 4 Insider Transactions: What Each Field Means →

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google

Add on Google Not now

Available on EDGAR 09/16/2026 - 04:21 PM Accepted by SEC EDGAR 09/16/2026 - 04:20 PM Learn about SEC filing dates

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^*

Spillane Robert F

(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)

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

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
09/14/2026

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)
			Code	V	Amount	(A) or (D)	Price
Common Stock	09/14/2026		M		10,363	A	$5.17	68,078	D
Common Stock	09/14/2026		S		10,363	D	$23.76(1)	57,715	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)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option (right to buy)	$5.17	09/14/2026		M			10,363	(2)	05/23/2027	Common Stock	10,363	$0(3)	0	D

Explanation of Responses:

1. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $23.75 to $23.7901, 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.

2. The stock options have fully vested and are immediately exercisable.

3. Granted as compensation for services.

Remarks:

	/s/ Aaron Saltz, attorney-in-fact	09/16/2026
	** 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)