X0508 4 2025-02-27 0001274494 FIRST SOLAR, INC. FSLR 0002052277 Theurer Nathan B. C/O FIRST SOLAR, INC. 350 WEST WASHINGTON STREET, SUITE 600 TEMPE AZ 85288 1 VP - Global Controller and CAO 1 Common Stock 2025-02-27 4 A 0 560 0 A 560 D Common Stock 2025-02-27 4 F 0 181 156.84 D 379 D Common Stock 2025-08-14 4 S 0 686 182.03 D 0 D Represents the acquisition of shares of common stock issued upon the vesting of the performance share units granted on March 15, 2022, which performance share unit awards were subject to vesting over an approximately three-year performance period contingent upon the achievement of certain performance objectives. Represents shares of common stock withheld by the Issuer to satisfy certain tax withholding obligations with the vesting of the performance share units. This transaction was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the reporting person on May 15, 2025. Shares sold include 379 shares from the February 27, 2025 acquisition described herein and 307 shares previously reported on the Form 4 filed March 18, 2025. /s/ Jason E. Dymbort, attorney-in-fact 2025-08-18