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

Date of ~~the~~Report ~~Securities~~(Date ~~Exchange~~of ~~Act~~earliest ofevent ~~1934~~reported) November 5, 2025

Date of Report (Date of earliest event reported) October 14, 2025

SOUTHWEST GAS HOLDINGS, INC.

(Exact name of registrant as specified in its charter)

Delaware

~~001-37976~~

~~81-3881866~~

001-37976

81-3881866

(State or other jurisdiction ofincorporation or organization)

(Commission File Number)

(I.R.S. EmployerIdentification No.)

(State or other jurisdiction of incorporation or organization)

(Commission File Number)

(I.R.S. Employer Identification No.)

8360 S. Durango Drive

Post Office Box 98510

Las Vegas, Nevada 89193-8510

(Address of principal executive offices) (Zip Code)

~~89193-8510~~Registrant's telephone number, including area code: (702) 876‑7237

(Zip Code)

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

Southwest Gas Holdings, Inc.:

Title of each class

Trading Symbol

Name of each exchange on which registered

Southwest Gas Holdings, Inc. Common Stock, $1 Par Value

SWX

New York Stock Exchange

Southwest Gas Corporation:

None.

Registrant’s telephone number, including area code: (702) 876-7237

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

Title of each class		TradingSymbol		Name of each exchangeon which registered
Southwest Gas Holdings, Inc. Common Stock, $1 Par Value		SWX		New York Stock Exchange

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))

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 12.0102 Results ~~Entry~~of ~~Into~~Operations aand ~~Material~~Financial ~~Definitive Agreement~~Condition.

On ~~October~~November 145, 2025, Southwest Gas Holdings, Inc. ~~(the~~released ~~“Company”)~~summary ~~and~~financial ~~Carl~~information C.to ~~Icahn and~~ the ~~persons~~general ~~and~~public, ~~entities~~including ~~listed~~the ~~therein~~investment ~~(collectively~~community, ~~the~~regarding ~~“Icahn~~operating ~~Group”~~performance ~~and~~for ~~together with~~ the ~~Company,~~quarter ~~the~~and ~~“Parties”)~~nine ~~entered~~months ~~into~~ended anSeptember 30, 2025. A ~~Amended~~copy ~~and~~of ~~Restated Cooperation Agreement (~~the ~~“Amended~~associated ~~Agreement”),~~press ~~which~~release ~~amends, restates, supersedes~~ and ~~replaces~~summary infinancial ~~its~~information ~~entirety~~is ~~that~~attached ~~certain~~hereto ~~Amended and Restated Cooperation Agreement, dated~~ as ofExhibit ~~October 15, 2024, by and between the Parties (the “Prior Agreement”)~~99.

InThis ~~accordance~~Form ~~with~~8-K ~~the terms of the Amended Agreement, the Company agreed with the Icahn Group, among other things, to nominate each of Andrew W. Evans, Henry P. Linginfelter, Ruby Sharma~~ and ~~Andrew J. Teno (each, an “Icahn Designee” and, collectively,~~ the ~~“Icahn~~attached ~~Designees”)~~exhibit ~~for~~are ~~election~~provided atunder ~~the~~Item ~~2026 annual meeting of stockholders of the Company (the “2026 Annual Meeting”)~~2.02 In addition, subject to qualifications set forth in the Amended Agreement, the Amended Agreement provides the standstill restrictions on the Icahn Group will remain in effect until, and the Amended Agreement will terminate upon, the later of ~~(x) the~~Form ~~conclusion~~8-K ~~of the 2026 Annual Meeting~~ and ~~(y) the~~are ~~earlier~~furnished of (1) immediately following the time at which Andrew J. Teno (or any Replacement Designee for Mr. Teno, as such term is defined in the Amended Agreement) is no longer serving on the Company’s board of directors (the “Board”) and (2) thirty (30) days prior to the expiration of the advance notice deadline for the submission of director nominees in connection with the Company’s 2027 Annual Meeting of Stockholders (as such term is defined in the Amended Agreement); provided, however, that the Amended Agreement will terminate automatically on the date on which the Board re-appoints as a director any former director of the Board (i.e., any person who was a director of the Board prior to the 2022 annual meeting of stockholders of the Company, but ~~was~~ not afiled ~~director of the Board immediately after the 2022 annual meeting of stockholders of the Company)~~with, ~~without~~ the ~~approval~~Securities ofand aExchange ~~majority of the Icahn Designees~~Commission.

~~Pursuant to the terms of the Amended Agreement, the Company further agreed with the Icahn Group to establish the record date for the 2026 Annual Meeting for a time within thirty (30)~~Item ~~days~~9.01 ofFinancial ~~March 3,~~Statements ~~2026.~~and Exhibits

~~Other~~(d) ~~than~~Exhibits: ~~the foregoing, the material terms of the Prior Agreement remain unchanged.~~

~~The~~99 Press ~~foregoing~~Release ~~description~~and ofsummary ~~the~~financial ~~Amended~~information ~~Agreement~~dated ~~is qualified in its entirety by reference to the full text of the Amended Agreement~~November 5, ~~a copy of which is attached hereto as Exhibit 10~~2025.~~1 and is incorporated by reference herein.~~

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

Exhibit No.		Description
10.1		Amended and Restated Cooperation Agreement, dated as of October 14, 2025, by and among the Icahn Group and Southwest Gas Holdings, Inc.*
104		Cover Page formatted in Inline XBRL

* Certain personal information in this exhibit has been omitted in accordance with Regulation S-K Item 601(a)(6).

SIGNATURES

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.

						SOUTHWEST GAS HOLDINGS, INC.
October 14, 2025						/s/ Catherine M. Mazzeo
November 5, 2025						/s/ Robert J. Stefani
						Catherine M. Mazzeo
						Robert J. Stefani
						Senior Vice President/Chief Legal, Safety & Compliance Officer and Corporate Secretary
						Senior Vice President/Chief Financial Officer

EXHIBIT INDEX


Exhibit No.						Description
99						Press Release and summary financial information dated November 5 , 2025.

Filing Compare · Southwest Gas Holdings, Inc.