Westlake Chemical Corporation
NYSE: WLK · BASIC MATERIALS · SPECIALTY CHEMICALS
Updated 2026-06-05
Westlake Chemical Corporation (WLK) Insider transactions
All transactions
| Date | Insider | Title | Type | Shares | Price | Value |
|---|---|---|---|---|---|---|
| 2026-05-13 | BENDER, MARK STEVEN | EVP & CFO | Sale | 5,284 | $97.34 | $514344.56 |
| 2026-05-12 | BENDER, MARK STEVEN | EVP & CFO | Sale | 13,164 | — | — |
| 2026-05-12 | BENDER, MARK STEVEN | EVP & CFO | Buy | 13,164 | — | — |
| 2026-04-02 | POWERS, BRIAN JOHN | SVP, PEM Segment Head | Buy | 1,961 | — | — |
| 2026-03-27 | BUESINGER, ROBERT F. | EVP, PEM Segment Head | Sale | 4,000 | $115.25 | $461000.00 |
| 2026-03-27 | BENDER, MARK STEVEN | EVP & CFO | Sale | 16,413 | $112.54 | $1.85M |
| 2026-02-27 | BENDER, MARK STEVEN | EVP & CFO | Sale | 6,494 | — | — |
| 2026-02-27 | BENDER, MARK STEVEN | EVP & CFO | Sale | 6,199 | — | — |
| 2026-02-27 | BENDER, MARK STEVEN | EVP & CFO | Sale | 16,988 | $100.91 | $1.71M |
| 2026-02-27 | BENDER, MARK STEVEN | EVP & CFO | Sale | 12,693 | $98.20 | $1.25M |
| 2026-02-27 | BENDER, MARK STEVEN | EVP & CFO | Buy | 6,494 | $86.54 | $561977.12 |
| 2026-02-27 | BENDER, MARK STEVEN | EVP & CFO | Buy | 6,199 | $65.81 | $407971.69 |
| 2026-02-27 | BENDER, MARK STEVEN | EVP & CFO | Sale | 421 | $101.52 | $42737.82 |
| 2026-02-20 | SZWEJBKA, SCOTT THOMAS | SVP, HIP Segment Head | Buy | 3,983 | — | — |
| 2026-02-20 | SZWEJBKA, SCOTT THOMAS | SVP, HIP Segment Head | Buy | 14,595 | — | — |
| 2026-02-20 | SZWEJBKA, SCOTT THOMAS | SVP, HIP Segment Head | Sale | 91 | $94.10 | $8563.10 |
| 2026-02-20 | PATEL, BHAVESH V. | Director | Buy | 1,852 | — | — |
| 2026-02-20 | HOLY, JEFFREY ADAM | VP and CAO | Buy | 2,540 | — | — |
| 2026-02-20 | HOLY, JEFFREY ADAM | VP and CAO | Buy | 1,199 | — | — |
| 2026-02-20 | HOLY, JEFFREY ADAM | VP and CAO | Buy | 4,394 | — | — |
| 2026-02-20 | HOLY, JEFFREY ADAM | VP and CAO | Sale | 81 | $94.10 | $7622.10 |
| 2026-02-20 | GILSON, JEAN-MARC | President and CEO | Buy | 29,784 | — | — |
| 2026-02-20 | GILSON, JEAN-MARC | President and CEO | Buy | 109,139 | — | — |
| 2026-02-20 | EDERINGTON, L. BENJAMIN | EVP, Legal & External Affairs | Buy | 7,002 | — | — |
| 2026-02-20 | EDERINGTON, L. BENJAMIN | EVP, Legal & External Affairs | Buy | 25,656 | — | — |
| 2026-02-20 | EDERINGTON, L. BENJAMIN | EVP, Legal & External Affairs | Sale | 357 | $94.10 | $33594.41 |
| 2026-02-20 | CHAO, JOHN TSUNG-CHEN | Director | Buy | 2,434 | — | — |
| 2026-02-20 | CHAO, JOHN TSUNG-CHEN | Director | Buy | 1,104 | — | — |
| 2026-02-20 | CHAO, JOHN TSUNG-CHEN | Director | Buy | 4,044 | — | — |
| 2026-02-20 | CHAO, JOHN TSUNG-CHEN | Director | Sale | 91 | $94.10 | $8563.10 |
| 2026-02-20 | CHAO, JAMES | Director, Senior Chairman | Buy | 7,472 | — | — |
| 2026-02-20 | CHAO, JAMES | Director, Senior Chairman | Buy | 27,382 | — | — |
| 2026-02-20 | CHAO, JAMES | Director, Senior Chairman | Sale | 1,569 | $94.10 | $147644.47 |
| 2026-02-20 | CHAO, ALBERT | Director, Executive Chairman | Buy | 14,945 | — | — |
| 2026-02-20 | CHAO, ALBERT | Director, Executive Chairman | Buy | 54,763 | — | — |
| 2026-02-20 | CHAO, ALBERT | Director, Executive Chairman | Sale | 2,501 | $94.10 | $235346.60 |
| 2026-02-20 | BUESINGER, ROBERT F. | EVP, PEM Segment Head | Buy | 5,281 | — | — |
| 2026-02-20 | BUESINGER, ROBERT F. | EVP, PEM Segment Head | Buy | 19,351 | — | — |
| 2026-02-20 | BUESINGER, ROBERT F. | EVP, PEM Segment Head | Sale | 326 | $94.10 | $30676.93 |
| 2026-02-20 | BENDER, MARK STEVEN | EVP & CFO | Buy | 7,747 | — | — |
| 2026-02-20 | BENDER, MARK STEVEN | EVP & CFO | Buy | 28,389 | — | — |
| 2026-02-20 | BENDER, MARK STEVEN | EVP & CFO | Sale | 445 | $94.10 | $41874.06 |
| 2026-02-19 | SZWEJBKA, SCOTT THOMAS | SVP, HIP Segment Head | Buy | 365 | — | — |
| 2026-02-19 | HOLY, JEFFREY ADAM | VP and CAO | Buy | 264 | — | — |
| 2026-02-19 | EDERINGTON, L. BENJAMIN | EVP, Legal & External Affairs | Buy | 1,425 | — | — |
| 2026-02-19 | CHAO, JOHN TSUNG-CHEN | Director | Buy | 213 | — | — |
| 2026-02-19 | CHAO, JAMES | Director, Senior Chairman | Buy | 3,884 | — | — |
| 2026-02-19 | CHAO, ALBERT | Director, Executive Chairman | Buy | 6,193 | — | — |
| 2026-02-19 | BUESINGER, ROBERT F. | EVP, PEM Segment Head | Buy | 1,301 | — | — |
| 2026-02-19 | BENDER, MARK STEVEN | EVP & CFO | Buy | 1,777 | — | — |
| 2026-02-18 | SZWEJBKA, SCOTT THOMAS | SVP, HIP Segment Head | Sale | 295 | $98.95 | $29190.25 |
| 2026-02-18 | HOLY, JEFFREY ADAM | VP and CAO | Sale | 213 | $98.95 | $21076.35 |
| 2026-02-18 | EDERINGTON, L. BENJAMIN | EVP, Legal & External Affairs | Sale | 978 | $98.95 | $96773.10 |
| 2026-02-18 | CHAO, JOHN TSUNG-CHEN | Director | Sale | 242 | $98.95 | $23945.90 |
| 2026-02-18 | CHAO, JAMES | Director, Senior Chairman | Sale | 2,664 | $98.95 | $263602.80 |
| 2026-02-18 | CHAO, ALBERT | Director, Executive Chairman | Sale | 5,089 | $98.95 | $503556.55 |
| 2026-02-18 | BUESINGER, ROBERT F. | EVP, PEM Segment Head | Sale | 903 | $98.95 | $89351.85 |
| 2026-02-18 | BENDER, MARK STEVEN | EVP & CFO | Sale | 1,209 | $98.95 | $119630.55 |
| 2026-02-17 | SZWEJBKA, SCOTT THOMAS | SVP, HIP Segment Head | Sale | 977 | — | — |
| 2026-02-17 | SZWEJBKA, SCOTT THOMAS | SVP, HIP Segment Head | Buy | 977 | — | — |
| 2026-02-17 | HOLY, JEFFREY ADAM | VP and CAO | Sale | 706 | — | — |
| 2026-02-17 | HOLY, JEFFREY ADAM | VP and CAO | Buy | 706 | — | — |
| 2026-02-17 | EDERINGTON, L. BENJAMIN | EVP, Legal & External Affairs | Sale | 3,809 | — | — |
| 2026-02-17 | EDERINGTON, L. BENJAMIN | EVP, Legal & External Affairs | Buy | 3,809 | — | — |
| 2026-02-17 | CHAO, JOHN TSUNG-CHEN | Director | Sale | 570 | — | — |
| 2026-02-17 | CHAO, JOHN TSUNG-CHEN | Director | Buy | 570 | — | — |
| 2026-02-17 | CHAO, JAMES | Director, Senior Chairman | Sale | 10,382 | — | — |
| 2026-02-17 | CHAO, JAMES | Director, Senior Chairman | Buy | 10,382 | — | — |
| 2026-02-17 | CHAO, ALBERT | Director, Executive Chairman | Sale | 16,555 | — | — |
| 2026-02-17 | CHAO, ALBERT | Director, Executive Chairman | Buy | 16,555 | — | — |
| 2026-02-17 | BUESINGER, ROBERT F. | EVP, PEM Segment Head | Sale | 3,478 | — | — |
| 2026-02-17 | BUESINGER, ROBERT F. | EVP, PEM Segment Head | Buy | 3,478 | — | — |
| 2026-02-17 | BENDER, MARK STEVEN | EVP & CFO | Sale | 4,751 | — | — |
| 2026-02-17 | BENDER, MARK STEVEN | EVP & CFO | Buy | 4,751 | — | — |
| 2025-12-22 | CHAO, ALBERT | Director, Executive Chairman | Sale | 81,673 | — | — |
| 2025-12-22 | CHAO, ALBERT | Director, Executive Chairman | Buy | 81,673 | $44.42 | $3.63M |
| 2025-12-22 | CHAO, ALBERT | Director, Executive Chairman | Sale | 30,604 | $73.80 | $2.26M |
| 2025-12-22 | CHAO, ALBERT | Director, Executive Chairman | Sale | 9,711 | $72.82 | $707135.60 |
| 2025-12-22 | CHAO, ALBERT | Director, Executive Chairman | Sale | 521 | $74.44 | $38784.80 |
| 2025-12-10 | CREGG, ROGER A | Director | Sale | 1,339 | — | — |
| 2025-12-10 | CREGG, ROGER A | Director | Buy | 1,339 | — | — |
| 2025-10-02 | SZWEJBKA, SCOTT THOMAS | SVP, HIP Segment Head | Sale | 3,842 | $76.70 | $294681.40 |
| 2025-10-01 | SZWEJBKA, SCOTT THOMAS | SVP, HIP Segment Head | Sale | 10,840 | — | — |
| 2025-10-01 | SZWEJBKA, SCOTT THOMAS | SVP, HIP Segment Head | Buy | 10,840 | — | — |
| 2025-08-28 | CHAO, JAMES | Director, Senior Chairman | Sale | 15,140 | — | — |
| 2025-08-09 | SHEETS, JEFFREY WAYNE | Director | Sale | 1,128 | — | — |
| 2025-08-09 | SHEETS, JEFFREY WAYNE | Director | Buy | 1,128 | — | — |
| 2025-08-09 | SABAT, CAROLYN CHAO | Director | Sale | 1,128 | — | — |
| 2025-08-09 | SABAT, CAROLYN CHAO | Director | Buy | 1,128 | — | — |
| 2025-08-09 | NORTHCUTT, R BRUCE | Director | Sale | 1,128 | — | — |
| 2025-08-09 | NORTHCUTT, R BRUCE | Director | Buy | 1,128 | — | — |
| 2025-08-09 | MCCOLLUM, MARK A | Director | Sale | 1,128 | — | — |
| 2025-08-09 | MCCOLLUM, MARK A | Director | Buy | 1,128 | — | — |
| 2025-08-09 | LUBEL, KIMBERLY S | Director | Sale | 1,128 | — | — |
| 2025-08-09 | LUBEL, KIMBERLY S | Director | Buy | 1,128 | — | — |
| 2025-08-09 | GRAFF, MICHAEL J | Director | Sale | 1,128 | — | — |
| 2025-08-09 | GRAFF, MICHAEL J | Director | Buy | 1,128 | — | — |
| 2025-08-09 | CHAO, DAVID TSUNG-HUNG | Director | Sale | 1,128 | — | — |
| 2025-08-09 | CHAO, DAVID TSUNG-HUNG | Director | Buy | 1,128 | — | — |
| 2025-08-09 | CHAO, CATHERINE T. | Director | Sale | 1,128 | — | — |
Frequently asked questions
Are WLK insiders buying or selling?
Over the transactions on record, WLK insiders have been net buyers, with about $10.79M in stock sold across 49 sales, against 3 open-market purchases.
Does insider selling at WLK mean the stock will fall?
Not by itself. Most executive selling is pre-scheduled through 10b5-1 plans filed months in advance, and insiders sell for diversification, taxes, and liquidity far more often than out of any view on the price. Insider buying is the stronger signal, especially when several insiders buy around the same time, because there is usually only one reason to put personal cash into the stock.
Which WLK insiders are selling the most?
Recent selling is concentrated in a few names. BENDER, MARK STEVEN accounts for the largest share on record, with about $5.53M sold. Selling by one or two individuals matters less than broad selling across the whole leadership team, which is the pattern worth watching.