144 0002013330 XXXXXXXX LIVE 0001069878 TREX CO INC 001-14649 2500 TREX WAY WINCHESTER VA 22601 5405426300 Rudolph Jacob T. SVP, CHRO Common Stock Citigroup Global Markets, Inc

390 Greenwich St New York NY 10013

1400 70000.00 103898729 06/25/2026 NYSE Common Stock 06/25/2026 Restricted Stock Vesting Trex Company, Inc. N 1400 06/25/2026 Services Rendered Y Under securities to be sold Date acquired and date of payment are on various dates. Shares were sold pursuant to an established 10b51 plan adopted March 2026 06/25/2026 03/05/2026 CONFORMED SIGNATURE ON FILE