TREX CO INC — Director's Dealing 2026

Feb 26, 2026

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: TREX CO INC (TREX)
CIK: 0001069878
Period of Report: 2026-02-24

Reporting Person: Gandhi Prithvi (SVP, Chief Financial Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2026-02-24	Common Stock	A	13848	$41.45	Acquired	44512	Direct
2026-02-24	Common Stock	A	13848	$41.45	Acquired	58360	Direct
2026-02-24	Common Stock	A	18094	$41.45	Acquired	76454	Direct

Footnotes

F1: This restricted stock unit award vests over a three-year period in three equal annual installments occurring March 1, 2027, March 1, 2028, and March 1, 2029.

F2: This restricted stock unit award is performance-based, and vests over a three-year period in three equal installments occurring March 1, 2027, March 1, 2028, and March 1, 2029. The number of shares set forth above is the target number of shares. The number of shares that will actually vest each year will be based upon performance against certain financial goals for the Company and will range from 0% to 200% of the target number of shares.

F3: This restricted stock unit award will vest in accordance with the terms of a Retention Agreement, dated February 24, 2026, between Trex Company, Inc. and Prithvi S. Gandhi; as further described in the Company's Annual Report on Form 10-K for the fiscal year ended December 31, 2025.