<SEC-DOCUMENT>0001104659-21-020590-index.html : 20210211 <SEC-HEADER>0001104659-21-020590.hdr.sgml : 20210211 <ACCEPTANCE-DATETIME>20210211150228 ACCESSION NUMBER: 0001104659-21-020590 CONFORMED SUBMISSION TYPE: SC 13G/A PUBLIC DOCUMENT COUNT: 1 FILED AS OF DATE: 20210211 DATE AS OF CHANGE: 20210211 SUBJECT COMPANY: COMPANY DATA: COMPANY CONFORMED NAME: TREX CO INC CENTRAL INDEX KEY: 0001069878 STANDARD INDUSTRIAL CLASSIFICATION: LUMBER & WOOD PRODUCTS (NO FURNITURE) [2400] IRS NUMBER: 541910453 STATE OF INCORPORATION: DE FISCAL YEAR END: 1231 FILING VALUES: FORM TYPE: SC 13G/A SEC ACT: 1934 Act SEC FILE NUMBER: 005-56187 FILM NUMBER: 21618982 BUSINESS ADDRESS: STREET 1: 160 EXETER DRIVE CITY: WINCHESTER STATE: VA ZIP: 22603-8605 BUSINESS PHONE: 5405426300 MAIL ADDRESS: STREET 1: 160 EXETER DRIVE CITY: WINCHESTER STATE: VA ZIP: 22603-8605 FILED BY: COMPANY DATA: COMPANY CONFORMED NAME: WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC CENTRAL INDEX KEY: 0001644956 IRS NUMBER: 472614791 STATE OF INCORPORATION: DE FISCAL YEAR END: 1231 FILING VALUES: FORM TYPE: SC 13G/A BUSINESS ADDRESS: STREET 1: 150 NORTH RIVERSIDE PLAZA CITY: CHICAGO STATE: IL ZIP: 60606 BUSINESS PHONE: 312-236-1600 MAIL ADDRESS: STREET 1: 150 NORTH RIVERSIDE PLAZA CITY: CHICAGO STATE: IL ZIP: 60606 </SEC-HEADER> <DOCUMENT> <TYPE>SC 13G/A <SEQUENCE>1 <FILENAME>tm216055-9_sc13ga.htm <DESCRIPTION>SC 13G/A <TEXT> Document 1 - file: tm216055-9_sc13ga.htm
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