[8-K] Magnite, Inc. Reports Material Event

Rhea-AI Filing Summary

Magnite, Inc. entered into a First Amendment to its Sublease with Zillow Group, Inc. that is expected to be effective as of November 1, 2025. The amendment expands the leased premises to add the entire 8th floor; prior to the amendment the leased premises consisted of the entire 9th floor. The company states the description in the notice is not complete and is qualified in its entirety by the full First Amendment, which will be filed as an exhibit to Magnite's Quarterly Report for the quarter ended September 30, 2025. No other terms, financial commitments, or lease costs are disclosed in this notice.

Positive

• Leased space expanded — the First Amendment adds the entire 8th floor to the company's leased premises effective November 1, 2025
• Formal disclosure commitment — the company will file the full First Amendment as an exhibit to its Quarterly Report for the quarter ended September 30, 2025

Negative

• None.

Insights

Corporate Real Estate Analyst

TL;DR Magnite amended its sublease to add the 8th floor, moving from lease of the 9th floor; key economic terms are not disclosed.

The First Amendment materially changes the physical scope of Magnite's leased space by adding the entire 8th floor effective November 1, 2025. The filing provides no details on rent, lease term, operating expenses, termination rights, or tenant improvements, so the financial impact on occupancy costs, headcount capacity, or capital expenditure needs cannot be assessed from this notice alone. The company will file the full amendment as an exhibit to its Quarterly Report for the period ended September 30, 2025, which should disclose the specific contract terms needed to evaluate the materiality to shareholders.

Securities/Corporate Governance Expert

TL;DR The disclosure notifies investors of a lease amendment expanding premises; it lacks financial and contractual detail required to judge materiality.

The 8-K appropriately alerts investors to a contractual amendment that alters leased premises. Because the notice explicitly defers to the full amendment to be filed with the quarterly report, investors should view this as a preliminary disclosure. From a governance and disclosure perspective, timely filing of the exhibit will be necessary to satisfy materiality and transparency standards; until then, the investor impact remains indeterminate based on the information provided.

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 OR 15(d) of the Securities Exchange Act of 1934

August 31, 2025

Date of Report (Date of earliest event reported)

MAGNITE, INC.

(Exact name of registrant as specified in its charter)

Delaware			001-36384			20-8881738
(State or other jurisdiction of incorporation)			(Commission File Number)			(IRS Employer Identification No.)
1250 Broadway, 15th Floor
New York, New York 10001
(Address of principal executive offices, including zip code)
(212) 243-2769
(Registrant’s telephone number, including area code)
Not applicable
(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐			Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
☐			Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
☐			Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
☐			Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class

Trading Symbol(s)

Name of each exchange on which registered

Common stock, par value $0.00001 per share

MGNI

Nasdaq Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company  ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.  ☐

Item 1.01.    Entry into a Material Definitive Agreement.

On August 31, 2025, Magnite, Inc. (the “Company”), a Delaware corporation, entered into a First Amendment (“First Amendment”) to the Sublease between Zillow Group, Inc. and the Company, dated September 21, 2021 (the “Sublease”). The First Amendment, which is expected to be effective as of November 1, 2025, among other things, expands the leased premises under the Sublease to add the entire 8th floor to the leased premises, which prior to the First Amendment consisted of the entire 9th floor.

The foregoing description of the First Amendment does not purport to be complete and is qualified in its entirety by reference to the full text of the First Amendment, which will be filed as an exhibit to the Company’s Quarterly Report on Form 10-Q for the quarter ended September 30, 2025.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

						MAGNITE, INC.
Date:			September 5, 2025			By:			/s/ David Day
									David Day
									Chief Financial Officer

FAQ

What did Magnite (MGNI) disclose in this 8-K?

Magnite disclosed it entered into a First Amendment to its Sublease with Zillow Group that expands the leased premises to include the entire 8th floor, expected effective November 1, 2025.

Does the 8-K state how the amendment affects Magnite's lease costs?

No. The notice does not disclose rent, lease term, operating expenses, or other financial terms.

Where can I find the full text of the First Amendment?

The company will file the full First Amendment as an exhibit to its Quarterly Report for the quarter ended September 30, 2025.

Was the leased premises changed from a different floor?

Yes. Prior to the First Amendment the leased premises consisted of the entire 9th floor; the amendment adds the entire 8th floor.

Is an effective date provided for the amendment?

Yes. The amendment is expected to be effective as of November 1, 2025.