Adam Dante Zambanini - 01 Mar 2026 Form 4 Insider Report for TREX CO INC (TREX)

Role: EVP, Chief Operating Officer
Signature: /s/ Amy M. Fernandez by power of attorney
Issuer symbol: TREX
Transactions as of: 01 Mar 2026
Net transactions value: -$272,378
Form type: 4
Filing time: 03 Mar 2026, 17:56:53 UTC
Previous filing: 25 Feb 2026
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Zambanini Adam Dante	EVP, Chief Operating Officer	2500 TREX WAY, C/O TREX COMPANY, INC., WINCHESTER	/s/ Amy M. Fernandez by power of attorney	03 Mar 2026	0001512909

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	TREX	Common Stock	Award	$150,065	+3,623	+1.5%	$41.42	244,713	01 Mar 2026	Direct	F1
transaction	TREX	Common Stock	Other	$79,858	-1,928	-0.79%	$41.42	242,785	01 Mar 2026	Direct	F2
transaction	TREX	Common Stock	Tax liability	$342,585	-8,271	-3.4%	$41.42	234,514	01 Mar 2026	Direct	F3

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Represents net share difference between target performance-based shares and actual vested shares, based upon actual performance of the Company.
F2	Represents the target number of performance-based restricted units which did not vest due to the performance condition not being satisfied.
F3	8,271 shares are being surrendered as allowed by the Company's 2023 Stock Incentive Plan to cover payment of taxes currently due on previously granted restricted stock units.