SWX · Southwest Gas Holdings, Inc.

Represents a prorated equity award granted on May 7, 2026 in connection with the reporting persons appointment as a director effective May 7, 2026.

Represents a prorated equity award granted on May 7, 2026 in connection with the reporting persons appointment as a director effective May 7, 2026.

Shares withheld to cover tax on settled Performance Stock Units delivered as a result of satisfaction of performance goals and reported on February 23, 2026.

Shares withheld to cover tax on settled Performance Stock Units delivered as a result of satisfaction of performance goals and reported on February 23, 2026.

Shares withheld to cover tax on settled Performance Stock Units delivered as a result of satisfaction of performance goals and reported on February 23, 2026.

Shares withheld to cover tax on settled Performance Stock Units delivered as a result of satisfaction of performance goals and reported on February 23, 2026.

Shares withheld to cover tax on settled Performance Stock Units delivered as a result of satisfaction of performance goals and reported on February 23, 2026.

Shares withheld to cover tax on settled Performance Stock Units delivered as a result of satisfaction of performance goals and reported on February 23, 2026.

Shares withheld to cover tax on settled Performance Stock Units delivered as a result of satisfaction of performance goals and reported on February 23, 2026.

Shares withheld to cover tax on settled Performance Stock Units delivered as a result of satisfaction of performance goals and reported on February 23, 2026.

Settled Performance Stock Units delivered to the reporting person as a result of satisfaction of the performance goal for the final vesting condition of the award.

Balance includes 1,123.038 shares acquired through exempt dividend reinvestment transactions.

Balance includes 283.574 shares acquired through exempt dividend reinvestment transactions.

Balance includes 215.249 shares acquired through exempt dividend reinvestment transactions.

Each restricted stock unit represents a contingent right to receive one share of SWX common stock. Restricted stock units vest in three annual installments (40%, 30%, 30%), assuming continued service.

Each restricted stock unit represents a contingent right to receive one share of SWX common stock. Restricted stock units vest in three annual installments (40%, 30%, 30%), assuming continued service.

Each restricted stock unit represents a contingent right to receive one share of SWX common stock. Restricted stock units vest in three annual installments (40%, 30%, 30%), assuming continued service.

Balance includes 215.249 shares acquired through exempt dividend reinvestment transactions.

Balance includes 497.053 shares acquired through exempt dividend reinvestment transactions.

Settled Performance Stock Units delivered to the reporting person three years after grant date as a result of satisfaction of performance goals.

Settled Performance Stock Units delivered to the reporting person three years after grant date as a result of satisfaction of performance goals.

Balance includes 165.188 shares acquired through exempt dividend reinvestment transactions.

Settled Performance Stock Units delivered to the reporting person three years after grant date as a result of satisfaction of performance goals.

Balance includes 215.249 shares acquired through exempt dividend reinvestment transactions.

Balance includes 11.726 shares acquired through exempt dividend reinvestment transactions.

Each restricted stock unit represents a contingent right to receive one share of SWX common stock. Restricted stock units vest in three annual installments (40%, 30%, 30%), assuming continued service.

Each restricted stock unit represents a contingent right to receive one share of SWX common stock. Restricted stock units vest in three annual installments (40%, 30%, 30%), assuming continued service.

Settled Performance Stock Units delivered to the reporting person three years after grant date as a result of satisfaction of performance goals.

Each restricted stock unit represents a contingent right to receive one share of SWX common stock. Restricted stock units vest in three annual installments (40%, 30%, 30%), assuming continued service.

Each restricted stock unit represents a contingent right to receive one share of SWX common stock. Restricted stock units vest in three annual installments (40%, 30%, 30%), assuming continued service.

Each restricted stock unit represents a contingent right to receive one share of SWX common stock. Restricted stock units vest in three annual installments (40%, 30%, 30%), assuming continued service.

Settled Performance Stock Units delivered to the reporting person three years after grant date as a result of satisfaction of performance goals.

Balance includes 298.573 shares acquired through exempt dividend reinvestment transactions.

Settled Performance Stock Units delivered to the reporting person three years after grant date as a result of satisfaction of performance goals.

Settled Performance Stock Units delivered to the reporting person three years after grant date as a result of satisfaction of performance goals.

This transaction is pursuant to a 10b5-1 Plan adopted on 09/10/2025.

Balance includes 4.987 shares acquired through exempt dividend reinvestment transactions.

Balance includes 172.623 shares acquired through exempt dividend reinvestment transactions.

Balance includes 10.915 shares acquired through exempt dividend reinvestment transactions.

Balance includes 2,656.892 shares acquired through exempt dividend reinvestment transactions.

Balance includes 348.695 shares acquired through exempt dividend reinvestment transactions.

Balance includes 174.673 shares acquired through exempt dividend reinvestment transactions.

Balance includes 688.277 shares acquired through exempt dividend reinvestment transactions.

Balance includes 490.729 shares acquired through exempt dividend reinvestment transactions.

Balance includes 597.707 shares acquired through exempt dividend reinvestment transactions.

This Form 4 is being filed by, and on behalf of, Mr. Carl C. Icahn, Icahn Partners LP ("Icahn Partners") and Icahn Partners Master Fund LP ("Icahn Master," and, collectively with Mr. Icahn and Icahn Partners, the "Reporting Persons").

Beckton Corp. ("Beckton") is the sole stockholder of Icahn Enterprises G.P. Inc. ("Icahn Enterprises GP"), which is the general partner of Icahn Enterprises Holdings L.P. ("Icahn Enterprises Holdings"). Icahn Enterprises Holdings is the sole member of AEPC Holdings LLC, which is the sole member of IPH GP LLC ("IPH"), which is the general partner of Icahn Capital LP ("Icahn Capital"). Icahn Capital is the general partner of each of Icahn Onshore LP ("Icahn Onshore") and Icahn Offshore LP ("Icahn Offshore"). Icahn Onshore is the general partner of Icahn Partners. Icahn Offshore is the general partner of Icahn Master.

Beckton is 100 percent owned by Mr. Icahn. As such, Mr. Icahn is in a position indirectly to determine the investment and voting decisions made by each of Icahn Partners and Icahn Master.

Each of Icahn Onshore, Icahn Capital, IPH, Icahn Enterprises Holdings, Icahn Enterprises GP, Beckton, and Mr. Icahn may be deemed to indirectly beneficially own (as that term is defined in Rule 13d-3 under Securities Exchange Act of 1934, as amended), the Shares of Southwest Gas Holdings, Inc. that Icahn Partners owns. Each of Icahn Onshore, Icahn Capital, IPH, Icahn Enterprises Holdings, Icahn Enterprises GP, Beckton, and Mr. Icahn disclaims beneficial ownership of such Shares except to the extent of their pecuniary interest therein, if any.

Each of Icahn Offshore, Icahn Capital, IPH, Icahn Enterprises Holdings, Icahn Enterprises GP, Beckton, and Mr. Icahn may be deemed to indirectly beneficially own the Shares which Icahn Master owns. Each of Icahn Offshore, Icahn Capital, IPH, Icahn Enterprises Holdings, Icahn Enterprises GP, Beckton, and Mr. Icahn disclaims beneficial ownership of such Shares except to the extent of their pecuniary interest therein, if any.

Reflects Shares sold to a market maker pursuant to Section 144(f)(1)(ii) of the Securities Act of 1933, as amended. After giving effect to the transactions above, Icahn Partners directly beneficially owns 3,419,167 Shares and Icahn Master directly beneficially owns 2,613,437 Shares.

Settled Performance Stock Units delivered to the reporting person as a result of satisfaction of the performance goal for the final vesting condition of the award.