| SC 13G/A | 2010-02-12 | WELLINGTON MANAGEMENT CO LLP | TREX CO INC | 2,089,155 | 13.6% | EDGAR |
| SC 13G | 2010-02-12 | SECURITY INVESTORS LLC | TREX CO INC | 814,676 | 5.3% | EDGAR |
| SC 13G | 2010-02-03 | J P MORGAN CHASE & CO | TREX CO INC | 887,085 | 5.7% | EDGAR |
| SC 13G | 2010-01-29 | BlackRock Inc. | TREX CO INC | 853,264 | 5.5% | EDGAR |
| SC 13G/A | 2010-01-26 | ROYCE & ASSOCIATES LLC | TREX CO INC | 916,040 | 6.0% | EDGAR |
| SC 13G | 2009-11-10 | WELLINGTON MANAGEMENT CO LLP | TREX CO INC | 1,788,609 | 11.6% | EDGAR |
| SC 13G/A | 2009-04-09 | PZENA INVESTMENT MANAGEMENT LLC | TREX CO INC | 754,439 | 4.9% | EDGAR |
| SC 13G/A | 2009-04-01 | O'SHAUGHNESSY ASSET MANAGEMENT, LLC | TREX CO INC | 721,599 | 4.7% | EDGAR |
| SC 13G/A | 2009-03-24 | O'SHAUGHNESSY ASSET MANAGEMENT, LLC | TREX CO INC | 1,005,137 | 6.6% | EDGAR |
| SC 13G/A | 2009-02-17 | PZENA INVESTMENT MANAGEMENT LLC | TREX CO INC | 862,956 | 5.6% | EDGAR |
| SC 13G/A | 2009-02-05 | RUTABAGA CAPITAL MANAGEMENT LLC/MA | TREX CO INC | 0 | 0.0% | EDGAR |
| SC 13G | 2009-02-05 | BARCLAYS GLOBAL INVESTORS NA /CA/ | TREX CO INC | 395,429 | 2.6% | EDGAR |
| SC 13G/A | 2009-01-30 | ROYCE & ASSOCIATES LLC | TREX CO INC | 1,074,600 | 7.0% | EDGAR |
| SC 13G/A | 2009-01-22 | Sterling Capital Management LLC | TREX CO INC | 0 | 0.0% | EDGAR |
| SC 13G/A | 2009-01-20 | Lapides Asset Management, LLC | TREX CO INC | 0 | 0.0% | EDGAR |
| SC 13G | 2009-01-12 | O'SHAUGHNESSY ASSET MANAGEMENT, LLC | TREX CO INC | 1,005,137 | 6.6% | EDGAR |
| SC 13G/A | 2008-09-10 | PZENA INVESTMENT MANAGEMENT LLC | TREX CO INC | 1,156,171 | 7.5% | EDGAR |
| SC 13G/A | 2008-03-06 | ROYCE & ASSOCIATES LLC | TREX CO INC | 1,529,400 | 10.1% | EDGAR |
| SC 13G/A | 2008-03-06 | MATHENY ROBERT G | TREX CO INC | 536,803 | 3.5% | EDGAR |
| SC 13G/A | 2008-02-14 | WELLINGTON MANAGEMENT CO LLP | TREX CO INC | 0 | 0.0% | EDGAR |